To determine the mass of zinc in the original sample of foot powder, we need to use stoichiometry and the given information about the masses of the precipitates obtained.
The balanced chemical equation for the reaction is:
[tex]3 ZnNH_{4} PO_{4}[/tex] + heat → [tex]Zn_{3} (PO_{4} )_{2}[/tex] + 3 [tex]NH_{4} VO_{3}[/tex] + 3 [tex]H_{2} O[/tex]
According to the equation, 3 moles of [tex]Zn_{3} (PO_{4} )_{2}[/tex] react to form 1 mole of [tex]Zn_{3} (PO_{4} )_{2}[/tex].
We must first determine the quantity of moles of [tex]ZnNH_{4} PO_{4}[/tex] obtained:
n([tex]ZnNH_{4} PO_{4}[/tex]) = m/M
where m = mass of [tex]ZnNH_{4} PO_{4}[/tex] obtained = 2.34 g
M = molar mass of [tex]ZnNH_{4} PO_{4}[/tex] = 243.3 g/mol
n([tex]ZnNH_{4} PO_{4}[/tex]) = 2.34 g / 243.3 g/mol = 0.00961 mol
Next, we can use the mole ratio from the balanced equation to calculate the number of moles of [tex]Zn_{3} (PO_{4} )_{2}[/tex] formed:
n([tex]Zn_{3} (PO_{4} )_{2}[/tex]) = n([tex]ZnNH_{4} PO_{4}[/tex]) / 3 = 0.00961 mol / 3 = 0.00320 mol
Finally, we can calculate the mass of zinc present in the original sample of foot powder:
m(Zn) = n([tex]Zn_{3} (PO_{4} )_{2}[/tex]) × M([tex]Zn_{3} (PO_{4} )_{2}[/tex]) × (1 mol Zn / 1 mol [tex]Zn_{3} (PO_{4} )_{2}[/tex])
where M([tex]Zn_{3} (PO_{4} )_{2}[/tex]) = molar mass of [tex]Zn_{3} (PO_{4} )_{2}[/tex]= 386.1 g/mol
m(Zn) = 0.00320 mol × 386.1 g/mol × (1 mol Zn / 1 mol [tex]Zn_{3} (PO_{4} )_{2}[/tex] ) = 1.24 g
Therefore, the mass of zinc present in the original sample of foot powder was approximately 1.24 grams.
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Complete Question:
What mass of zinc was present in the original sample of foot powder if 2.34 grams of [tex]ZnNH_{4} PO_{4}[/tex] precipitate were obtained, and upon heating, the precipitate converted to 1.97 grams of [tex]Zn_{3} (PO_{4} )_{2}[/tex]?
A gas system fitted is fitted with a piston. Calculate the total change in internal energy if 894 J are released when the gas is compressed 1.00 L against an external pressure of 966 torr.
The total change in internal energy of the gas system fitted with a piston is 886 J when the gas is compressed 1.00 L against an external pressure of 966 torr.
To calculate the total change in internal energy of the gas system fitted with a piston, we need to use the first law of thermodynamics, which states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system.
In this case, we know that 894 J of heat are released when the gas is compressed 1.00 L against an external pressure of 966 torr. We also know that the work done by the system is equal to the external pressure multiplied by the change in volume.
To calculate the change in volume, we need to convert the pressure from torr to Pascals (Pa) and then use the ideal gas law, PV=nRT, to find the final volume.
First, we convert 966 torr to Pa by multiplying by 133.3 Pa/torr, which gives us 128,578 Pa.
Next, we need to find the number of moles of gas present in the system. We can use the ideal gas law to do this:
PV=nRT
n = PV/RT
where P is the pressure, V is the initial volume (which we assume is equal to the final volume), R is the gas constant (8.31 J/mol*K), and T is the temperature (which we assume is constant).
Plugging in the values, we get:
n = (101,325 Pa)(1.00 L)/(8.31 J/mol*K)(298 K) = 0.0403 mol
Now we can use the ideal gas law to find the final volume:
PV=nRT
V = nRT/P
V = (0.0403 mol)(8.31 J/mol*K)(298 K)/(128,578 Pa) = [tex]0.00106 m^3[/tex]
The change in volume is therefore:
[tex]\triangle V = V_f - V_i = 0.00106 m^3 - 0.00100 m^3 = 6.00 *10^{-5} m^3[/tex]
Finally, we can calculate the work done by the system:
W = PΔV
[tex]= (128,578 Pa)(6.00 * 10^{-5} m^3)[/tex]
= 7.71 J
Now we can use the first law of thermodynamics to find the total change in internal energy:
ΔU = Q - W = 894 J - 7.71 J = 886 J
Therefore, the total change in internal energy of the gas system fitted with a piston is 886 J.
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Rank from largest to smallest atomic radius. To rank items as equivalent, overlap them. View Available Hint(s) Reset Help O s Se Te Ро Largest Smallest
The ranking from largest to smallest atomic radius is: Po > Te > Se > O.
To rank the atomic radii of O (Oxygen), S (Sulfur), Se (Selenium), Te (Tellurium), and Po (Polonium) from largest to smallest, we can use the periodic table trends. As you move down a group (vertical column), the atomic radius generally increases due to the addition of electron shells.
Based on this trend, the order from largest to smallest atomic radius is:
Po > Te > Se > S > O
Write the balanced NET ionic equation for the reaction when silver perchlorate and aluminum chloride are mixed in aqueous solution. If no reaction occurs, simply write only NR.
The balanced net ionic equation is:
Ag⁺(aq) + ClO₄⁻(aq) + Al³⁺(aq) + 3Cl⁻(aq) → AgCl(s) + AlCl₃(aq)
The balanced net ionic equation for the reaction between silver perchlorate and aluminum chloride in aqueous solution is shown above. In this reaction, the silver ion (Ag⁺) and perchlorate ion (ClO₄⁻) from silver perchlorate (AgClO₄) react with the aluminum ion (Al³⁺) and chloride ion (Cl⁻) from aluminum chloride (AlCl₃) to form solid silver chloride (AgCl) and aluminum chloride in aqueous solution (AlCl₃).
The net ionic equation shows only the species that participate in the reaction and are involved in the formation of the product (AgCl), while the spectator ions (Cl⁻ and Al³⁺) are omitted.
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use equation 7.24 and the data in chapter 4 (table 4.2) to calculate the standard molar entropy of cl2 (g) at 298.15 k. compare your answer with the experimental value of 223.1 jmol-1k-1
The standard molar entropy of cl2 (g) at 298.15 k is -0.05 J/mol K which is very small and may even be within the experimental error.
To calculate the standard molar entropy of Cl2 (g) at 298.15 K, we can use equation 7.24:
ΔS° = ΣS°(products) - ΣS°(reactants)
Using the data from chapter 4, we can find the standard molar entropy of Cl2 (g) and its elements:
S°(Cl2, g) = 223.07 J/mol K
S°(Cl2, l) = 223.15 J/mol K
S°(Cl, g) = 223.06 J/mol K
Since we are only interested in the gas phase, we will use the value for S°(Cl2, g). The equation for the formation of Cl2 (g) from its elements is:
Cl2 (g) = Cl (g) + Cl (g)
So, the reactants are two Cl (g) atoms, and the products are one Cl2 (g) molecule. Therefore:
ΔS° = S°(Cl2, g) - 2S°(Cl, g)
ΔS° = 223.07 J/mol K - 2(223.06 J/mol K)
ΔS° = -0.05 J/mol K
This value is very small and may even be within the experimental error, but it indicates that the formation of Cl2 (g) from its elements slightly decreases the entropy of the system.
Comparing this result to the experimental value of 223.1 J/mol K, we see that there is a small difference, which may be due to the approximations made in the calculation or the experimental error. However, the two values are very close, which indicates that the theoretical model used to calculate the standard molar entropy is a good approximation for this system.
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Complete Question:
a solution is prepared by mixing 25.0 ml of 6.0 m hcl with 45.0 ml of 3.0 m hno3. what is [h ] in the resulting solution?
To find the [H+] concentration in the resulting solution when 25.0 mL of 6.0 M HCl is mixed with 45.0 mL of 3.0 M HNO3. Hence, the [H+] concentration in the resulting solution when 25.0 mL of 6.0 M HCl is mixed with 45.0 mL of 3.0 M HNO3 is approximately 4.07 M.
Follow these steps:
1. Calculate the moles of H+ ions contributed by each solution:
- Moles of H+ from HCl: (25.0 mL)(6.0 mol/L) = 150 mmol
- Moles of H+ from HNO3: (45.0 mL)(3.0 mol/L) = 135 mmol
2. Determine the total moles of H+ ions in the resulting solution:
- Total moles of H+ = moles from HCl + moles from HNO3 = 150 mmol + 135 mmol = 285 mmol
3. Calculate the total volume of the resulting solution:
- Total volume = volume of HCl + volume of HNO3 = 25.0 mL + 45.0 mL = 70.0 mL
4. Calculate the [H+] concentration in the resulting solution:
- [H+] = (total moles of H+)/(total volume) = (285 mmol)/(70.0 mL) = 4.07 M (rounded to two decimal places)
So, the [H+] concentration in the resulting solution when 25.0 mL of 6.0 M HCl is mixed with 45.0 mL of 3.0 M HNO3 is approximately 4.07 M.
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if the actual yield of chromium (|||) chloride is 337g what is the percent yield?
(please include work)
thanks !
You must compare the actual yield of the product to the theoretical yield that was calculated based on the stoichiometry of the reactants in order to determine the percent yield of a reaction.
Stoichiometry can be used to determine the theoretical yield if the initial reactants and the reaction's balanced equation were known.
For instance, if the reaction's balanced equation is
[tex]3 Cr + 2 AlCl_3 = 2 Al + 3 CrCl_3.[/tex]
And you might determine the potential yield of chromium (Cr) as follows if you started with 200 grams of aluminum (Al) and enough chromium (|||) chloride (CrCl3) to react completely with the aluminum:
Determine the aluminum's moles:
moles Al = mass of Al / molar mass of Al
= 200 g / 26.98 g/mol
= 7.41 mol
Calculate the number of moles of chromium to be formed using the stoichiometry of the balanced equation:
moles Cr = (3/2) moles CrCl3
= (3/2) (moles Al / 2)
= (3/2) (7.41 mol / 2)
= 11.11 mol
Using the molar mass of chromium, convert the moles of chromium to mass:
mass of Cr = moles Cr x molar mass of Cr
= 11.11 mol x 52.00 g/mol
= 577.8 g
Therefore, 577.8 g of chromium are theoretically produced.
Now, you can use the following formula to determine the percent yield:
(Actual Yield / Theoretical Yield) x 100% equals percent yield
The % yield would be: if the actual yield of chromium (|||) chloride is 337g.
yield calculated as (337 g/577.2 g) x 100% = 58.3%
Therefore, the reaction's percent yield is 58.3%. This suggests that only 58.3% of the theoretical yield that may have been attained if the reaction had proceeded to completion was actually produced in the experiment.
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Select all the true statements regarding the products obtained from the following reactions.A) (Z)-hex-3-ene treated with D2 in the presence of Pd.Product mixture is racemicProduct is the meso-formProduct solution is optically activeProduct solution is optically inactiveProducts are enantiomersProducts are diastereomersB) (E)-hex-3-ene treated with D2 in the presence of Pd.Product mixture is racemicProduct is the meso-formProduct solution is optically activeProduct solution is optically inactiveProducts are enantiomersProducts are diastereomersC) (Z)-hex-3-ene treated with Br2 in the cold and dark.Product mixture is racemicProduct is the meso-formProduct solution is optically activeProduct solution is optically inactiveProducts are enantiomersProducts are diastereomersD) (E)-hex-3-ene treated with Br2 in the cold and dark.Product mixture is racemicProduct is the meso-formProduct solution is optically activeProduct solution is optically inactiveProducts are enantiomersProducts are diastereomers
The true statements regarding the products obtained from the following reactions:
1) (Z)-hex-3-ene treated with D2 in the presence of Pd:
Product is the meso-formProduct solution is optically inactive2) (E)-hex-3-ene treated with D2 in the presence of Pd.
Product Mixture is racemicProduct solution is optically inactiveProducts are enantiomers3) (Z)-hex-3-ene treated with Br2 in the cold and dark.
Product mixture is racemicProduct solution is optically inactiveProducts are enantiomers4) (E)-hex-3-ene treated with Br2 in the cold and dark.
Product is the meso-formProduct solution is optically inactiveChemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
Chemical reactions are a fundamental component of life itself, as well as technology and culture. Burning fuels, smelting iron, creating glass and pottery, brewing beer, producing wine, and making cheese are just a few examples of ancient processes that involved chemical reactions. The Earth's geology, the atmosphere, the seas, and a wide variety of intricate processes that take place in all living systems are rife with chemical reactions.
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The true statements regarding the products obtained from the following reactions:
1) (Z)-hex-3-ene treated with D2 in the presence of Pd:
Product is the meso-formProduct solution is optically inactive2) (E)-hex-3-ene treated with D2 in the presence of Pd.
Product Mixture is racemicProduct solution is optically inactiveProducts are enantiomers3) (Z)-hex-3-ene treated with Br2 in the cold and dark.
Product mixture is racemicProduct solution is optically inactiveProducts are enantiomers4) (E)-hex-3-ene treated with Br2 in the cold and dark.
Product is the meso-formProduct solution is optically inactiveChemical reaction, the transformation of one or more chemicals (the reactants) into one or more distinct compounds (the products). Chemical elements or chemical compounds make up substances. In a chemical reaction, the atoms that make up the reactants are rearranged to produce various products.
Chemical reactions are a fundamental component of life itself, as well as technology and culture. Burning fuels, smelting iron, creating glass and pottery, brewing beer, producing wine, and making cheese are just a few examples of ancient processes that involved chemical reactions. The Earth's geology, the atmosphere, the seas, and a wide variety of intricate processes that take place in all living systems are rife with chemical reactions.
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a solution has [ag ] of 2.9 × 10-4 m and 0.225 m of (s2o3)2−. what is the concentration of ag after the solution reaches equilibrium? kf of ag(s2o3)23− = 2.9 × 1013
The concentration of Ag+ at equilibrium is 4.6 × 10^-8 M.
Use the equilibrium constant expression for the reaction between Ag+ and (S2O3)2-:
Ag+(aq) + 2(S2O3)2-(aq) ⇌ Ag(S2O3)23-(aq)
The equilibrium constant expression is:
Kc = [Ag(S2O3)23-]/[Ag+][S2O3]2-
We know the kf value for this reaction, which is related to Kc by the following equation:
kf = Kc(RT)^(2-2n)
where R is the gas constant, T is the temperature in Kelvin, and n is the number of moles of electrons transferred in the balanced chemical equation. In this case, n = 2.
We can rearrange this equation to solve for Kc:
Kc = kf/(RT)^(2-2n)
Kc = (2.9 × 10^13)/[(0.0821)(298)^2]
Kc = 3.3 × 10^9
Now we can use this value of Kc to calculate the concentration of Ag+ at equilibrium:
Kc = [Ag(S2O3)23-]/[Ag+][S2O3]2-
3.3 × 10^9 = (2.9 × 10^-4 + x)(0.225 - 2x)^2 / x(0.225 - x)
Simplifying this expression and solving for x, we get:
x = 4.6 × 10^-8 M
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25g of marble were completely decompose by heat. (i)Write an equation for the decomposition reaction. (ii)Calculate the mass of each Product formed (iii) Determine the volume of gas Produced at S.T.P
(i) CaCO3 CaO + CO2 is the equation for the breakdown process of marble (CaCO3). (ii) Each product will have a mass equal to the weight of the marble used, or 25 g. Therefore, the mass of CaO and CO2 that are produced will both be 25 g.
(iii) The ideal gas law equation, PV = nRT, can be used to determine the volume of gas produced at S.T.P. where P is pressure, V is volume, n is the number of moles of gas, R is the ideal gas constant, and T is temperature.
We can determine the number of moles of CO2 produced using the formula since the mass of CO2 formed is 25 g.n is therefore 25/44 = 0.568 mol. The volume of gas created at STP may now be determined using the ideal gas law equation: V = (0.568 mol)(8.314 J/mol.K)(273 K)/(101.3 kPa) = 16.9 L. As a result, 16.9 L of petrol are produced at STP.
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For the endothermic reaction
CaCO3 (s) <-----> CaO (s) + CO2 (g)
Le Chtelier's principle predicts that __________ will result in an increase in the number of moles of CO2 at equilibrium.
a. increasing the temperature
b. decreasing the temperature
c. increasing the pressure
d. removing some of the CaCO3(s)
e. adding more CaCO3 (s)
Le Chatelier's principle predicts that (a) increasing the temperature will result in an increase in the number of moles of CO₂ at equilibrium.
What is Le Chatelier's principle?According to Le Chatelier's principle, when a system at equilibrium is subjected to a stress, it will shift its equilibrium position in a way that tends to counteract that stress. For the given endothermic reaction, the reaction will absorb heat when it proceeds in the forward direction.
Therefore, increasing the temperature of the system will shift the equilibrium to the right, in the direction of the products, to absorb some of the added heat. As a result, there will be an increase in the number of moles of CO₂ at equilibrium.
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explain the purpose of using ph 2.0 for retention and dilute ammonia for extraction
The purpose of using a pH of 2.0 for retention and dilute ammonia for extraction is to enhance the separation and recovery of specific compounds in a sample.
Using a pH of 2.0 for retention serves the following purposes:
1. It promotes the ionization of acidic compounds, making them more readily retained on a reversed-phase column in chromatography. This enhances the separation of the compounds in the sample.
2. It maintains a constant pH environment, which is crucial for reproducible retention times and peak shapes in chromatographic analysis.
Dilute ammonia for extraction is used for the following reasons:
1. It acts as a weak base, which helps to neutralize acidic compounds and make them more soluble in an aqueous phase. This assists in the extraction of the target compounds from a sample matrix.
2. It can also help to selectively extract and separate basic compounds from a mixture. By adjusting the pH of the extraction solvent, you can control which compounds are extracted and which are not.
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Which, if any, of the following metals would not be capable of acting as a sacrificial anode when used with iron E degree Fe = -0.44 V; all E degree values refer to the M^2+/M half-cell reactions. A) manganese, Mn, E degree = -1.18 V B) magnesium, Mg, E degree = 2.37 V C) zine, Zn, E degree = - 0.76 V D) cadmium, Cd, E degree = -0.40 V E) All of these metals are capable of acting as sacrificial anodes with iron.
The metal that would not be capable of acting as a sacrificial anode when used with iron is B) magnesium, Mg, E° = 2.37 V.
For a metal to act as a sacrificial anode with iron, it needs to have a more negative E° value than iron (E° Fe = -0.44 V).
The more negative E° value indicates that the metal will corrode more easily and preferentially compared to iron. In this case, magnesium has a more positive E° value (2.37 V), which means it will not corrode more easily than iron and thus cannot act as a sacrificial anode.
The other metals (A) manganese, Mn, E° = -1.18 V; C) zinc, Zn, E° = -0.76 V; and D) cadmium, Cd, E° = -0.40 V, have more negative E° values than iron, so they can act as sacrificial anodes.
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what is the ph of a solution of 9.1x10-6 m hbr?
The pH of a 9.1 x 10^-6 M solution of [tex]HB_{r}[/tex] is approximately 5.04. To find the pH of a 9.1 x 10^-6 M solution of [tex]HB_{r}[/tex], you can use the following equation: HBr + [tex]H_{2}O[/tex]→ [tex]H_{3}O[/tex]+ + [tex]B_{r}[/tex]-
The acid dissociation constant (Ka) for [tex]HB_{r}[/tex] is very high, meaning it is a strong acid and will dissociate completely in water. Therefore, we can assume that the concentration of [tex]H_{3}O[/tex]+ ions in the solution is equal to the initial concentration of [tex]HB_{r}[/tex].
So, the concentration of [tex]H_{3}O[/tex]+ ions in the solution is:
[[tex]H_{3}O[/tex]+] = 9.1 x 10^-6 M
To find the pH of the solution, you can use the following equation:
pH = -log[[tex]H_{3}O[/tex]+]
Substituting the value of [[tex]H_{3}O[/tex]+] into the equation, we get:
pH = -log(9.1 x 10^-6)
pH = 5.04
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calculate the ph of 1.1 m (c2h5)2nh(aq) given that its kb = 6.9×10-4.
The pH of the 1.1 M (C2H5)2NH(aq) solution is approximately 12.44.
To calculate the pH of a 1.1 M (C2H5)2NH(aq) solution, given its Kb value of 6.9×10⁻⁴, first determine the pOH and then convert it to pH. Use the formula:
Kb = [NH+] [OH-] / [(C2H5)2NH]
Since the initial concentration of (C2H5)2NH is 1.1 M, and assuming that x is the concentration of the dissociated species, the equation becomes:
6.9×10⁻⁴ = x² / (1.1 - x)
Approximate the equation, assuming x is small compared to 1.1:
6.9×10⁻⁴ ≈ x² / 1.1
Solve for x (which represents [OH-]):
x = √(6.9×10⁻⁴ × 1.1) ≈ 0.0275
Now calculate the pOH:
pOH = -log10(0.0275) ≈ 1.56
Finally, convert the pOH to pH:
pH = 14 - pOH ≈ 14 - 1.56 = 12.44
Thus, the pH of the 1.1 M (C2H5)2NH(aq) solution is approximately 12.44.
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Lithium aluminum hydride also can reduce aldehydes and ketones to the corresponding alcohols. However, simply substituting it for sodium borohydride in the lab manual $ procedure would not work,and in fact could be dangerous Why would lithium aluminum hydride not be compatible with the lab manual s reaction conditions?
Lithium aluminum hydride (LiAlH₄) cannot be directly substituted for sodium borohydride (NaBH₄) in the lab manual's procedure to reduce aldehydes and ketones to the corresponding alcohols because LiAlH₄ is a much stronger and more reactive reducing agent than NaBH₄.
Lithium aluminum hydride is a much more powerful reducing agent compared to sodium borohydride, and as a result, it requires more careful handling and specific reaction conditions. Lithium aluminum hydride reacts violently with water and can generate highly flammable hydrogen gas, which can lead to dangerous situations in the lab if not properly handled. Additionally, the reaction conditions for lithium aluminum hydride reduction are typically more rigorous, including higher temperatures and longer reaction times.
Therefore, simply substituting lithium aluminum hydride for sodium borohydride in the lab manual procedure would not be appropriate or safe. Specific precautions and modifications to the procedure would need to be taken to ensure safe and successful use of lithium aluminum hydride as a reducing agent.
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By how much does the cell potential change when Qis decreased by a factor of 10 for a reaction in which v 2 at 298 K?
When Q is decreased by a factor of 10, the cell potential changes by 0.0592/n volts.
This is based on the Nernst equation, which relates the cell potential to the standard cell potential and the concentrations of reactants and products.
In this case, since Q is decreasing, the concentration of products is increasing relative to the concentration of reactants, and this shift in equilibrium results in a change in the cell potential.
The value of n represents the number of electrons involved in the reaction, and v 2 refers to the stoichiometric coefficient of the species in question.
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Which of the following statements is not true? a. In polar protic solvents, nucleophilicity decreases down a column of the periodic table as the size of the anion increases. b. Nucleophilicity is affected by the solvent used in a substitution reaction. c. Polar protic solvents are capable of intermolecular hydrogen bonding. d. Polar protic solvents solvate both cations and anions.
The statement that is not true is a. In polar protic solvents, nucleophilicity decreases down a column of the periodic table as the size of the anion increases. So, the correct option is option a.
In polar protic solvents, nucleophilicity decreases down a column of the periodic table as the size of the anion increases, which is not true.
In fact, nucleophilicity increases down a column of the periodic table in polar protic solvents, as larger anions are better able to stabilize the positive charge that results from the nucleophilic attack.
Therefore, as size increases going down the group, nucleophilicity also increases.
The other statements b. Nucleophilicity is affected by the solvent used in a substitution reaction, c. Polar protic solvents are capable of intermolecular hydrogen bonding, and d. Polar protic solvents solvate both cations and anions are all true.
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Calculate the pH at 25°C of a 0.29M solution of ammonium bromide NH4Br . Note that ammonia NH3 is a weak base with a pKb of 4.75 . Round your answer to 1 decimal place.
The ammonium bromide solution in this case is an aqueous solution of NH4Br.
The ammonium ion, NH4+, is the conjugate acid of the weak base ammonia (NH3), which means that NH4+ will donate a proton in water.
The corresponding pKa value for NH4+ is found to be 9.24, while the pKb value for NH3 is found to be 4.75.
Here is the solution to this problem:
We know that;
NH4+ + H2O → NH3 + H3O+Kb(NH3) = Kw/Ka(NH4+)
Thus, Kb(NH3) = 10^-14/10^-9.24 = 1.8 × 10^-5.
The expression for Kb is given below:
Kb = [NH3][OH-]/[NH4+]
We can neglect the contribution from the water.
Thus, Kb = [NH3]^2/[NH4+][OH-]
Let us define the moles of NH3 and NH4+ present in 1 L of the solution as x.
Then, moles of OH- present in 1 L of the solution is (x + 0.29).
The expression for Kb now becomes:
Kb = x^2 / (0.29 x) + x + 1.8 × 10^-5
Solving for x, we get x = 5.6 × 10^-5 M.
So, the concentration of NH3 is 5.6 × 10^-5 M, and the concentration of NH4+ is 0.29 M.
The equilibrium expression for NH3 is given by:
NH3 + H2O ⇌ NH4+ + OH-pKa(NH4+) = pKb(NH3) + pKw= 4.75 + 14 = 18.75
pH = 14 - pOH = 14 - (- 8.35) = 22.35
But pH should not be more than 14 so, pH = 14 - 8.35= 5.65 at 25°C.
The pH of the solution is 5.7
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the molar enthaly of fusion of ice at 273.15 k and 1 atm is 6010 j mol and v under the same condition is -1.63 cm. determine the value of dt/dp for ice at its normal melting point
The value of dT/dP for ice at its normal melting point is approximately -7.4 x 10⁻³ K/Pa and the molar enthalpy of fusion of ice at 273.15 k and 1 atm is 6010 j mol and v under the same condition is -1.63 cm.
To determine the value of dt/dp for ice at its normal melting point, we need to use the Clapeyron equation:
dt/dp = ΔHfus / TΔV
Where ΔHfus is the molar enthalpy of fusion, T is the temperature in Kelvin, and ΔV is the molar volume change during the phase transition.
Substituting the given values, we get:
dt/dp = (6010 J/mol) / (273.15 K x (-1.63 x 10^-6 m^3/mol))
Simplifying this expression, we get:
dt/dp = -13.4 K/MPa
Therefore, the value of dt/dp for ice at its normal melting point is -13.4 K/MPa.
To determine the value of dT/dP for ice at its normal melting point, you can use the Clapeyron equation:
dT/dP = ΔH_fus / (T * ΔV)
where dT/dP is the change in temperature with respect to pressure, ΔH_fus is the molar enthalpy of fusion (6010 J/mol), T is the temperature (273.15 K), and ΔV is the change in volume (-1.63 cm³/mol, converted to m³/mol).
First, convert ΔV from cm³/mol to m³/mol:
-1.63 cm³/mol * (1 m³ / 10⁶ cm³) = -1.63 * 10⁻⁶ m³/mol
Now, plug the values into the Clapeyron equation:
dT/dP = (6010 J/mol) / (273.15 K * -1.63 * 10⁻⁶ m³/mol)
dT/dP ≈ -7.4 x 10⁻³ K/Pa
The value of dT/dP for ice at its normal melting point is approximately -7.4 x 10⁻³ K/Pa.
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If 2.00 mL of 0.850 M NaOH are added to 1.000 L of 0.300 M CaCl2, what is the value of the reaction quotient and will precipitation occur?
The reaction between NaOH and CaCl₂ will form Ca(OH)₂ precipitate.
The balanced chemical equation is NaOH + CaCl₂ → Ca(OH)₂ + 2NaCl. The initial concentration of Ca²⁺ is 0.300 M, and the initial concentration of OH⁻ is (2.00 mL/1000 mL)(0.850 mol/L) = 0.0017 M.
The reaction quotient, Q, can be calculated by multiplying the concentrations of the products and dividing by the concentrations of the reactants raised to their stoichiometric coefficients.
Therefore, Q = [Ca²⁺][OH⁻]²/[Na⁺]²[Cl⁻]² = (0.300)(0.0017)²/0.85² = 5.5 × 10⁻⁴. Since Q is less than the solubility product, Ksp, of Ca(OH)₂ (1.6 × 10⁻⁵), precipitation will not occur.
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What do you think are the advantages and disadvantages of mining an asteroid in space?
(THIS IS FOR SCIENCE)
Advantage: mining asteroids in space would be able to gain a larger amount resources from one asteroid then a mine for 1 month and it would be able to some what stop the destruction of earth's natural resources
Disadvantage: finding and asteroid close to earth then stopping it and mining will be very expensive and transporting it back even if calculations were in place to these things then it would will take time for and asteroid to come near
Which one of the following molecules is not possible?a.BrF5b.NF5c.CH₂Cl2d. TeF6e.OF 2
TeF6 is the correct response. This is because atoms typically form molecules with eight electrons in each valence shell, in accordance with the octet rule.
TeF6 has six fluorine atoms, however there aren't enough valence electrons on the tellurium atom to create a stable molecule.
Atoms create and break chemical bonds during chemical reactions. Reactants are the molecules that initiate a chemical reaction, and products are the compounds that are created as a result of the reaction.
Combustion, breakdown, single-replacement, double-replacement, and combinations are the five fundamental types of chemical reactions. You can classify a reaction into one of these groups by studying the reactants and products.
While copper and oxygen go through a synthesis process, calcium sulphate goes through a double displacement reaction. Carbon and copper oxide undergo one displacement reaction.
It follows that the first reaction is a double displacement reaction, the second is a synthesis process, and the third is a single displacement reaction.
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what is the order in which the following compounds would be eluted from an hplc column containing a reversed-phase packing? (a) benzene, diethyl ether, n-hexane
(b) acetone, dichloroethane, acetamide.
Order in which the compounds would be eluted from an hplc column containing a reversed-phase -
(a) benzene > diethyl ether > n-hexane.
(b) acetamide > acetone > dichloroethane.
For a reversed-phase HPLC column, the compounds with the highest hydrophobicity will be retained the longest, and those with the lowest hydrophobicity will elute first. In other words, the order of elution will be the opposite of the order of polarity.
(a) The order of decreasing hydrophobicity for the compounds is benzene > diethyl ether > n-hexane. Therefore, n-hexane will elute first, followed by diethyl ether, and then benzene.
(b) The order of decreasing hydrophobicity for the compounds is acetamide > acetone > dichloroethane. Therefore, dichloroethane will elute first, followed by acetone, and then acetamide.
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Please help with these 3 questions!!!
1) How many atoms are contained in 0.55 g of Ni?
2) How many moles of Ti are in 5.50 × 1024 atoms of Ti?
3) How many atoms are in 3 molecules of H2CO?
Answer:
1. To determine the number of atoms in 0.55 g of Ni, we need to use the molar mass of Ni and Avogadro's number. The molar mass of Ni is 58.69 g/mol.
First, we need to find the number of moles of Ni in 0.55 g:
moles of Ni = mass of Ni / molar mass of Ni
moles of Ni = 0.55 g / 58.69 g/mol
moles of Ni = 0.009367 mol
Next, we can use Avogadro's number to convert from moles to atoms:
number of atoms = moles of Ni x Avogadro's number
number of atoms = 0.009367 mol x 6.022 x 10^23 atoms/mol
number of atoms = 5.63 x 10^21 atoms
Therefore, there are 5.63 x 10^21 atoms in 0.55 g of Ni.
2. To determine the number of moles of Ti in 5.50 x 10^24 atoms of Ti, we need to use Avogadro's number.
First, we need to convert the number of atoms to moles:
moles of Ti = number of atoms of Ti / Avogadro's number
moles of Ti = 5.50 x 10^24 atoms / 6.022 x 10^23 atoms/mol
moles of Ti = 9.13 moles
Therefore, there are 9.13 moles of Ti in 5.50 x 10^24 atoms of Ti.
3. To determine the number of atoms in 3 molecules of H2CO, we need to use the molecular formula of H2CO and Avogadro's number.
The molecular formula of H2CO indicates that there are 5 atoms in each molecule (2 hydrogen atoms, 1 carbon atom, and 2 oxygen atoms).
To determine the total number of atoms in 3 molecules of H2CO, we can multiply the number of atoms per molecule by the number of molecules:
total number of atoms = number of atoms per molecule x number of molecules
total number of atoms = 5 atoms/molecule x 3 molecules
total number of atoms = 15 atoms
Therefore, there are 15 atoms in 3 molecules of H2CO.
How many milliliters of oxygen are necessary to form 64.5 grams of sulfur trioxide gas during the
combustion of sulfur?
2S + 3O3 -> 2SO3
Calculate the wavelength of a 50.0 kg runner moving at 2.00 m/s.
\Calculating the wavelength of a runner weighing 50.0 kg and travelling at a speed of 2.00 m/s is not easy. Direct calculation of the runner's wavelength is not possible.
We must first determine the frequency of the runner's motion in order to determine the wavelength of the runner. The frequency of a motion is the number of times it occurs in a certain amount of time. Hertz (Hz) is the unit of measurement.
The formula f = v/, where f is the frequency, v is the velocity, and is the wavelength, can be used to determine the frequency of a runner's motion. In this instance, the wavelength is unknown and the velocity is 2.00 m/s.
With the specified values entered, we have = 2.00 m/s / 50.0 kg, or 0.04 m. This is the runner's motion's wavelength.
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what is the maximum amount of moles of p2o5 that can theoretically be made from 112g of o2 and excess phosphrus
The maximum amount of moles of P2O5 that can be theoretically be made from 112g of O2 and excess Phosphorus is 1.4 mole.
To determine the maximum amount of moles of P2O5 that can be produced from 112g of O2 and excess phosphorus, you'll need to use stoichiometry. Firstly, we need to write the balanced chemical equation for the reaction between O2 and phosphorus, which is
P4 + 5O2 → 2P2O5.
Then, we need to convert the given mass of O2 to moles, which is 112g O2 * (1 mol O2 / 32g O2) = 3.5 mol O2.
Using the stoichiometry from the balanced equation, we can find the moles of P2O5 produced, which is (3.5 mol O2) * (2 mol P2O5 / 5 mol O2) = 1.4 mol P2O5. Therefore, the maximum amount of moles of P2O5 that can be theoretically produced from 112g of O2 and excess phosphorus is 1.4 mol. This means that if we have an unlimited amount of phosphorus, we can produce up to 1.4 moles of P2O5 using 112g of O2.
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Is it possible for a native protein to be entirely irregular - that is, without α
helices,B sheets, or other repetitive secondary structure? Calculate the length in angstroms of a 100-residue segment of the
α keratin coiled-coil. Show your work.
No, it is not possible for a native protein to be entirely irregular that is, without α helices, B sheets or other repetitive secondary structure. The length of a 100-residue segment of the α keratin coiled-coil is 150 angstroms.
It is highly unlikely for a native protein to be entirely irregular without any α-helices, β-sheets, or other repetitive secondary structures. Most proteins consist of a combination of these structures, which are critical for protein folding and stability.
Now let's calculate the length in angstroms of a 100-residue segment of the α-keratin coiled-coil.
1. The α-keratin coiled-coil is a right-handed helix formed by two α-helices wrapped around each other. Each α-helix has 3.6 residues per turn.
2. To find the number of turns in the 100-residue segment, divide 100 residues by 3.6 residues per turn: 100 ÷ 3.6 ≈ 27.8 turns.
3. The rise per residue in an α-helix is 1.5 angstroms.
4. Multiply the rise per residue by the number of residues to obtain the length of the 100-residue segment: 1.5 angstroms/residue × 100 residues ≈ 150 angstroms.
So, the length of a 100-residue segment of the α-keratin coiled-coil is approximately 150 angstroms.
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using the volume of the second equivalence point, find the moles of acid present and the molar mass of the unknown acid. (moles naoh needed to reach the second equivalence point.____Moles of unknown acid. ____Molar mass of unknown acid. _____
Molar mass of unknown acid = quantity of acid used / moles of unknown acid. Molar mass of unknown acid = volume of second equivalence point / 2.
The second equivalence point happens once NaOH has neutralised all of the acid in the solution and all that is left is NaOH. Because NaOH is a potent base, it totally dissociates in solution and interacts with one mole of acid for every mole of NaOH present. Since there are two moles of acid in the solution, two moles of NaOH are required to achieve the second equivalence point. We divide the volume of the second equivalence point by two to determine the moles of the unknown acid. With this information, we can determine how many moles of acid are in the solution at the second equivalence point. Knowing the mass of the unknown acid is necessary to determine its molar mass.
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the predicted van't hoff factor for a calcium chloride solution, cacl₂(aq), is a) 1 b) 2 c) 3 d) 4 e) 0
The predicted van't Hoff factor for a calcium chloride solution, CaCl₂(aq), is c) 3.
The quantity of ions a solute dissociates into during solvent dissolution is known as the van't Hoff factor (i). A solute's impact on associated properties, such as osmotic pressure, relative vapor pressure reduction, boiling-point elevation, and freezing-point depression, is measured by the van 't Hoff factor i. The van 't Hoff factor measures the difference between the concentration of a substance determined by its mass and the actual concentration of particles created as the substance dissolves. Calcium chloride, CaCl₂, dissociates into one calcium ion (Ca²⁺) and two chloride ions (2 Cl⁻) when it dissolves in water. Therefore, the van't Hoff factor for CaCl₂ is 1 + 2 = 3.
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