Answer:
Impurities will be trapped in the crystals of the benzoic acid crystallized in this manner.
Explanation:
After benzoic acid is dissolved in hot water, it should have been allowed to cool gradually before it is transferred into an ice bath.
This gradual cooling will aid the separation of impurities so that when the vessel is now submerged in an ice bath, only pure benzoic acid is recrystalized.
If the vessel is immediately submerged into an ice bath, impurities will be trapped in the crystals of the benzoic acid.
Which phrase describes an irregular galaxy?
Given that O2 is paramagnetic and has a bond order of 2, and its highest occupied molecular orbital is antibonding, what would be the expected bond orders for O22- and O22
Answer:
Bond order of O22- = 1
Bond order of O22+ = 3
Explanation:
The bond order is given by;
1/2(number of bonding - number of anti bonding electrons).
In O22- , there are ten bonding and eight anti bonding electrons giving a bond order of 1 from; 1/2 (10 - 8) = 1
Similarly, for O22+ , we have ten bonding and four antibonding electrons, hence;
1/2 (10 - 4) = 3
Write the equality and conversion factors, and identify the numbers as exact or give the number of significant figures for which of the following:A. The Daily Value (DV) for iodine is 150 mcg.B. The nitrate level in well water was 32 ppm.C. Gold jewelary contains 58% gold by mass.D. The price of a litre of milk is $1.65.
Which element has a greater
ionization energy Manganese (Mn) or Selenium (Se)?
Answer:
manganese has greater ionization energy than Selenium
What is the pH of a weak acid that is 0.2% ionized in a 0.2 M solution?
Answer:
pH=3.40
Explanation:
For this question, we can start with the general ionization reaction of a general acid:
[tex]HA~<->~A^-~+~H^+[/tex]
The acids can produce the hydronium ion ([tex]H^+[/tex]). If we can to calculate the pH we have to use the equation:
[tex]pH=-Log[H^+][/tex]
So, if we want to calculate the pH value we have to know the concentration of the hydronium ion. For this, we can check the percentage of ionization. If we have 0.2 % of ionization, we will have only 0.2 % of hydronium ions from the initial concentration. In other words, we can calculate the concentration of [tex]H^+[/tex], if we do the 0.2% of the initial concentration, so:
[tex]0.2~M*\frac{0.2}{100}~=~0.0004~M[/tex]
With the concentration we can calculate the pH:
[tex]pH=-Log[0.0004~M]~=~3.40[/tex]
The pH value is 3.40
I hope it helps!
Calculate the volume of a sample of mercury with a density of 14.6 g/mL and a mass of 1.00 g.
The answer is assumed to be in mL. Please include a numeric value only with significant figures
Answer:
hiiiiiiiijsiosoaplq
The table below shows air pressure measurements taken at set altitudes above sea level. What fact about Earth’s atmosphere best explains this data according to the table? Question 3 options: As altitude increases in the atmosphere, temperature changes from layer to layer. As altitude increases, there is less air pushing down from above, which decreases the pressure. As altitude increases, the composition of the atmosphere changes so that lighter-weight gases make up the majority of the air. At higher altitudes, there is less water vapor in the air which changes the air pressure.
Answer: As altitude increases, there is less air pushing down from above, which decreases the pressure.
Explanation:
Atmospheric pressure is the result of air particles being pulled to the surface of the Earth by gravity. As they are pulled, they will exert more pressure on the Earth and this is what atmospheric pressure is.
It makes sense therefore that as we move higher into the atmosphere, the atmospheric pressure will decrease because less air particles are exerting pressure as we go further off the ground.
Another way to look at it is that there is air in the earth's atmosphere and all that air has weight that is pushing down on us. As we go higher into the atmosphere, there'll be less air pushing down on us so the weight will be less.
Answer:
A as te altitude increases
Explanation:
Consider an ion with the symbol X2+ formed from a representative element. (5.2, 5.3)a. What is the group number of the element?b. What is the electron-dot symbol of the element?c. If X is in Period 3, what is the element?d. What is the formula of the compound formed from X and the nitride ion?
Answer:
a) the element belongs to group 2
b) see image attached
c) Magnesium
d) X3N2
Explanation:
Any ion with the formula X^2+ was derived from group 2 elements. The group two element found in period 3 is magnesium alone.
Since the nitride ion has a valency of -3 and X^2+ has a valency of +2 , then a compound formed between X^2+ and the nitride ion will have the formula X3N2.
a. The group number of the element can be determined by knowing the charge of the ion. In the ion X2+ has a charge of 2+. Since representative elements typically form ions with charges equal to their group numbers, we can conclude that the group number of the element X is 2.
b. The electron-dot symbol, also known as Lewis dot symbol, represents the valence electrons of an element. Since X is a representative element in Group 2, it has two valence electrons.
c. If X is in Period 3, it could be one of the elements from Group 2 in that period. The most likely element would be Magnesium (Mg), as it is the representative element in Group 2 of Period 3.
d. The nitride ion has a charge of 3-. To form a neutral compound, the charges of X and the nitride ion must balance out. Since X has a charge of 2+ and the nitride ion has a charge of 3-, we need two X ions to balance the charge of three nitride ions. Therefore, the formula of the compound formed from X and the nitride ion is X3N2.
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Select the correct statement about thermochemical equations from the following: Select one:
a. The specific heat capacity of all substances involved in the chemical reaction are listed to the right of the balanced chemical equation.
b. Because the enthalpy change of the reaction depends on the states of matter of the substances, they must be shown for each substance in the equation.
c. Positive values for the enthalpy change of a reaction indicate that the reaction released energy.
d. If the chemical reaction is reversed, then the arithmetic sign of the change in enthalpy stays the same.
Answer:
Because the enthalpy change of the reaction depends on the states of matter of the substances, they must be shown for each substance in the equation.
Explanation:
The enthalpy of a substance depends on the particular state of matter in which it occurs.
Therefore, in a thermo chemical equation, all the states of matters for all the chemical species in the equation must be accurately written so that the thermo chemical equation can be meaningful.
The correct statement about thermochemical equations is the enthalpy
change of the reaction depends on the states of matter of the substances,
they must be shown for each substance in the equation.
Enthalpy is defined as the heat change that occurs in a reaction or the sum
of the internal energy present. It is associated with change in matter and is
dependent on the physical states of the reactants and products.
This is the reason why the physical states such as solid, liquid, gas etc have
to be shown in a thermochemical equation.
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How many millimoles of Cr2O72- ions and K1+ ions are present in 483. mL of a 0.0750 M K2Cr2O7?1. mmolCr2O72-
2. mmol K1+
Answer:
72.45 mmol K⁺ and 36.225 mmol Cr₂O₇²⁻
Explanation:
It is possible to obtain millimoles of a substantce by the multiplication of molarity times milliliters of the solution.
In the solution that is 0.0750M K₂Cr₂O₇:
K⁺ = 0.0750M * 2 = 0.150M
Cr₂O₇²⁻ = 0.0750M
The millimoles of these ions are:
Millimoles K⁺:
483mL * 0.150M = 72.45 mmol K⁺
Millimoles Cr₂O₇²⁻:
483mL * 0.075M = 36.225 mmol Cr₂O₇²⁻
Convert 75 mL of water to gallons (show work)
Answer:
0.01981 gallons.
Explanation:
In this problem, we need to convert 75 mL of water to gallons.
We know that, 1 gallon = 3785.41 mL
To convert 75 mL to gallons, we must use to the unitary method such that,
1 mL = (1/3785.41) gallon
So,
[tex]75\ mL=75\times \dfrac{1}{3785.41}\\\\=0.01981\ \text{gallons}[/tex]
So, there are 0.01981 gallons in 75 mL of water.
An object has a mass of 295 lbs. Convert this into kilograms (show work) ((last question))
Explanation:
kg = Ibs/2.2046 (from internet)
kg = 295/2.2046
= 133.81 kg
What is the scientific method and how does it work?
Answer:
scientists use the scientific method to collect measurable, empirical evidence in an experiment related to a hypothesis. The process of the scientific method involves making conjectures.
What is the systematic name of Mg(NO3)2?A) Manganese nitrite.B) Magnesium nitrite.C) Magnesium nitrate.D) Manganese nitrate.
Please answer ASAP >_<
What does xylem do in a plant?
•transport food
•transport water
•prevent water loss
•perform photosynthesis
Answer:
The correct answer is B. Transport water.
Explanation:
I did this quiz. :)
Xylem transport water. Therefore, the correct option is option B among all the given options. The vascular tissue of plants called xylem.
What is xylem?The vascular tissue of plants called xylem transports water plus dissolving minerals from the roots towards the rest of the plant while also offering structural support. The tracheary components, a collection of specialized, water-conducting cells, make up xylem tissue.
All vascular plants, along with the seedless club mosses, fern, horsetails, all angiosperms (flowering plants), and gymnosperms, include xylem in addition to phloem (tissue that transports glucose from the leaves to the rest of the plant) (plants with seeds unenclosed in an ovary). Xylem transport water.
Therefore, the correct option is option B.
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When a piece of metal mass of 54.52 g is dropped into a graduated cylinder containing 23.44 mL of water, the water level rises to 28.85 mL. What is the density of the metal? Answer in units of g/cm3
Answer:
Density = 10.01 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]From the question
mass of metal = 54.52 g
Volume of metal = new volume - original volume of water in the cylinder
That's
new volume = 28.85 mL
original volume of water = 23.44 mL
Volume of metal
= 28.85 - 23.44 = 5.41 mL
Next we convert the volume from mL to cm³
1 mL = 1 cm³
5.41 mL = 5.41 cm³
Substitute the values into the above formula and solve
That's
[tex]Density = \frac{54.52}{5 .41} \\ = 10.07763[/tex]We have the final answer as
Density = 10.01 g/cm³Hope this helps you
What phase would this substance be in at a pressure of 1.25atm and a temperature of 700C
Answer:
i dont have much detail, but im pretty sure it would be at a boil/vaporizing phase.
Two substances, A and B, with the same melting point. How can you determine if they are the same without using any form of spectroscopy? Explain in detail.
Answer:
Simply carry out the mixed melting point procedure
1 here grind the two substances mix them
2.take note of the melting point of the mixture this is P
3 also get the original product from a different source okay this is Q
4.so I the melting point of P = Q then they represent a similar compound
5. But if melting point of P is not equal to Q then one of the compounds is P is acting as an impurity so they are not the same
The compound has been similar or not has been determined with the determination of the shift in the melting point of the mixture of the two compounds.
The melting point can be defined as the temperature of the substance when it has been converted from the solid state to the liquid state.
The two substances were found to have the same melting point. The compounds have been determined whether they are similar or not by the determination of the melting point of the combined mixtures.
The compounds A and B have been mixed together, and the melting point has been determined. The similar compounds in mixing will give the same melting point. While if the compounds are different, there has been a shift in the melting point of the mixture.
Thus, the compound has been similar or not has been determined with the determination of the shift in the melting point of the mixture of the two compounds.
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Which of the following correctly lists the compounds in order of decreasing acidity?
A) H2O > HCCH > NH3 > CH3CH3
B) HCCH > H2O > NH3 > CH3CH3
C) CH3CH3 > HCCH > NH3 > H2O
D) CH3CH3 > HCCH > H2O > NH3
E) H2O > NH3 > HCCH > CH3CH3
Answer:
A) H2O > HCCH > NH3 > CH3CH3
Explanation:
H2O is known as a neural compound which a pH close to 7.0. This however makes it more acidic due to it having the lowest pH when compared to the others in the option.
The other options however have their acidic strength as follows: HCCH > NH3 > CH3CH3. This explains why the pattern of decreasing acidic strength is H2O > HCCH > NH3 > CH3CH3
One gallon of gasoline in an automobiles engine produces on average 9.50 kg of carbon dioxide, which is a greenhouse gas; that is, it promotes the warming of Earth's atmosphere. Calculate the annual production of carbon dioxide in kilograms if there are exactly 40.0 million cars in the United States and each car covers a distance of 7930 mi at a consumption rate of 23.6 miles per gallon. Enter your answer in scientific notation.
Answer:
The value is [tex]U =1.3908 *10^{11} \ kg [/tex]
Explanation:
From the question we are told that
mass of carbon dioxide produced by one gallon of gasoline is [tex]m = 9.50 \ kg[/tex]
The number of cars is [tex]N = 40 \ million = 40 *10^{6} \ cars[/tex]
The distance covered by each car is [tex]d = 7930 \ mi[/tex]
The rate is [tex]R = 23.6 \ mi/ gallon[/tex]
Generally the amount of gasoline used by one car is mathematically represented as
[tex]G = \frac{d}{R}[/tex]
=> [tex]G = \frac{7930}{23.6}[/tex]
=> [tex]G = 366 \ gallons [/tex]
Generally the amount of gasoline used by N cars is
[tex]H = N * G[/tex]
=> [tex]H = 40*10^{6} * 366[/tex]
=> [tex]H = 1.464*10^{10} \ gallons [/tex]
Generally the annual production of carbon dioxide is mathematically represented as
[tex]U = m * H[/tex]
=> [tex]U =9.50 * 1.464*10^{10}[/tex]
=> [tex]U =1.3908 *10^{11} \ kg [/tex]
Question 2
1 pts
Which value below correctly expresses the answer to this calculation:
(Reminder: consider sig figs)
310 x 0.00189 x 42.0 =
A 1.00-mole sample of C6H12O6 was placed in a vat with 100 g of yeast. If 32.3 grams of C2H5OH was obtained, what was the percent yield of C2H5OH?
Answer:
y = 35.06 %.
Explanation:
The reaction of fermentation is:
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (1)
From the reaction (1) we have that 1 mol of C₆H₁₂O₆ produces 2 moles of C₂H₅OH, then the number of moles of C₂H₅OH is:
[tex]n = \frac{2 moles C_{2}H_{5}OH}{1 mol C_{6}H_{12}O_{6}}*1 mol C_{6}H_{12}O_{6} = 2 moles C_{2}H_{5}OH[/tex]
Now, we need to find the mass of C₂H₅OH:
[tex]m = n*M = 2 moles*46.07 g/mol = 92.14 g[/tex]
Finally, the percent yield of C₂H₅OH is:
[tex] \% = \frac{32.3 g}{92.14 g}*100 = 35.06 \% [/tex]
Therefore, the percent yield of C₂H₅OH is 35.06 %.
I hope it helps you!
The percent yield of C2H5OH should be 35.06% also it have the 1.00 moles.
Calculation of the percent yield:Since
The reaction of fermentation should be
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ (1)
Here 1 mol of C₆H₁₂O₆ generated 2 moles of C₂H₅OH, so the number of moles of C₂H₅OH should be
= 2 moles / 1mole * 1 mole
= 2 moles C₂H₅OH
So here the percent yield should be
= 32.3 / (2 * 4607)
= 32.3 / 92.14
= 35.06%
Hence, The percent yield of C2H5OH should be 35.06% also it have the 1.00 moles.
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Perform the following conversion: 6.1 × 103 K (the surface temperature of the Sun) to °F and °C. Pay attention to the number of significant figures in this problem. (Enter your answers in scientific notation.)
Answer:
[tex]\°C=5.8x10^3\°C[/tex]
[tex]\°F=1.1x10^4\°F[/tex]
Explanation:
Hello,
In this case, for the calculation of the temperature in degree Celsius we subtract 273.15 to the given temperature in kelvins:
[tex]\°C=6100-273.15\\\\\°C=5.8x10^3\°C[/tex]
Next, by applying the following equation we compute it in degree Fahrenheit:
[tex]\°F=(5.8x10^{3}*9/5) + 32\\\\\°F=1.1x10^4\°F[/tex]
Clearly, since the initial unit has two significant figures the computed units also show two significant figures.
Regards.
What is a substance?
ASAPPP
Answer:
A particular kind of matter
Explanation:
How you could use the scientific method to learn whether water really does take longer to boil if you are watching it.
Answer:
Please find the detailed explanation below
Explanation:
A scientific method is a sequence of steps that is used to solve a problem. Every scientific method begins with a problem that needs to be solved.
Hence, in order to determine whether water really does take longer to boil if you are watching it, we employ the steps involved in a scientific method.
1) Ask a question/Make observation: This must initiate the process. The observation/question made here is that DOES WATER TAKE LONGER TIME TO BOIL WHEN WATCHED?
2. Formulating hypothesis; an hypothesis is a testable prediction of a possible solution to the stated problem. In this case, an hypothesis could read: IF water is watched while boiling, THEN it will take a longer time to boil. A hypothesis must be tested for it to be proved or disproved.
3. Test hypothesis: The formulated hypothesis is tested via conducting an experiment. The set up of the experiment can involve one group where water is boiled while watching it and another where water is boiled without watching. The former group is called Experimental group, while the latter group is called Control group. The time it takes for each group of water to boil will be recorded.
The independent variable (manipulated variable) will be the WATCHING, while the dependent variable (tested/responding variable) will be the TIME IT TAKES FOR WATER TO BOIL
4. Analyse the data; the data refers to the recorded time for each group of water. This will be analysed and compared.
5. Make conclusion; the conclusion depends on the result, which is the recorded time for each group of boiled water. Based on the result, the hypothesis can either be rejected or accepted. For example, if the control group boils faster than the experimental group, our hypothesis will be accepted but if otherwise, the hypothesis will be rejected.
Therefore, via the scientific method, it can be determined if it really takes longer time for water to boil while watched.
I need help on these two questions please!!!
Answer:
5. A. Shape and volume
6. A. Solid to liquid
7. C. Gas
Rotation about a carbon-carbon double bond does not readily occur because: __________.1) the overlap of the p orbitals of the carbon-carbon π bond would be lost2) the double bond is much shorter and therefore more difficult to rotate3) the overlap of the sp2 orbitals of the carbon-carbon σ bond would be lost4) the double bond is much stronger and therefore more difficult to rotate
Answer:
1) The overlap of the p orbitals of the carbon-carbon π bond would be lost
Explanation:
Unlike simple bonds, a double bond can not rotate, since it is not possible to twist the ends of the molecule without breaking the π bond.
In the structure of but-2-ene present in the attachment, we can see the two isomers, cis and trans. These isomers cannot be interconverted by rotation around the carbon-carbon double bond without breaking the π bond.
Read the scenario, then answer the questions. A 2 kg ball is thrown upward with a velocity of 15 m/s. What is the kinetic energy of the ball as it is being thrown? J What is the potential energy of the ball when it gets to its maximum height just before falling back to the ground? J
Answer:
225 for both answers
Explanation:
The only reason i know this is because i got it wrong. 225
Answer:
225J on both of the questions.
All organisms need a place to live that provides
Answer:
Living Space get food or nutrients, water, and shelter. No matter where an organism lives, it must provide what it needs to survive.
Explanation:All organisms need a place to live, and store energy to take care of itself.
Which set contains non-equivalent members?A) enthalpy and heat contentB) endothermic reaction and +HC) exothermic reaction and -HD) kinetic energy and energy of motionE) high energy and high stability
Answer:
E
Explanation:
Here in this question, what we will do is to select which of the pairs that do not correlate.
A. Enthalpy and heat content
This two terms are at par with each other. By definition, the enthalpy of a system simply is the total amount of heat content it has.
B. Endothermic reaction and +H
These two terms are at par with each other. An endothermic reaction is one in which heat is absorbed from the surroundings. It has a positive value for the heat content i.e the enthalpy is positive and thus H is positive.
C. Exothermic reaction and -H
An exothermic reaction is one in which heat is released to the environment. It usually has a negative value for the enthalpy and thus the value of H is negative.
D. High energy and High Stability
These two terms are not at par. When an entity has or is of high energy, it is usually unstable. An entity at a higher energy level will not be stable until it goes to a lower level of energy.
Thus higher energy level is associated with lesser stability while lower energy levels are associated with higher stability. The lesser the energy of an entity, the higher its stability.
This makes the option our answer.