Answer:
10.41 g
Explanation:
ml and cm^3 are generally interchangeable
15 cm^3 * . 694 g/cm^3 = 10.41 g
of an investigation, students were asked to prepare a sodium hydroxide solution of a certain molarity. The students were given a
of procedures. Which procedure will result in 750 mL of 1.5 M NaOH solution?
issolving 1.13 g of NaOH in enough water to make up to 750 mL of solution
ssolving 45 g of NaOH in enough water to make up to 750 mL of solution
ssolving 40 g of NaOH in 1 L of water
solving 1.13 g of NaOH in 0.750 L of water
The correct procedure is:
Dissolving 45 g of NaOH in enough water to make up to 750 mL of solution
What is molarity?This is defined as the mole of solute per unit litre of solution. Mathematically, it can be expressed as:
Molarity = mole / Volume
How to determine the mole of NaOH Volume = 750 mL = 750 / 1000 = 0.75 L Molarity = 1.5 MMole of NaOH =?Mole = Molarity x Volume
Mole of NaOH = 1.5 × 0.75
Mole of NaOH = 1.125 mole
How to determine the mass of NaOH Mole of NaOH = 1.125 moleMolar mass of NaOH = 40 g/mol Mass of NaOH =?Mass = mole × molar mass
Mass of NaOH = 1.125 × 40
Mass of NaOH = 45 g
Thus, to obtain 750 mL of 1.5 M NaOH solution, 45 g of NaOH will be dissolved in enough water to make up to 750 mL of solution
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Which is an unreliable source?
A scientist who studies dinosaurs presents her research on velociraptors at a science convention.
An advertisement for acne medication claims it can clear up acne in less than one week.
An article on the Centers for Disease Control and Prevention (CDC) website discusses the salmonella bacteria.
A chemistry teacher discusses possible projects for the upcoming science fair.
The source that is unreliable is an advertisement for acne medication claims it can clear up acne in less than one week.
What are citable sources?Citable sources are those sources that are gotten from places that are proven to be of good standards and not from mere claims such as:
Science journalsprofessional organizationsgovernment agenciesTherefore, the source that is unreliable is an advertisement for acne medication claims it can clear up acne in less than one week.
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Consider the following representation of a reaction mechanism.
Step 1: A+ AC + E (slow)
Step 2: E+BA+ D (fast)
Overall reaction: A + B C + D
→>>
What should appear in the rate law for the reaction above?
O only A and B because they are reactants in the overall reaction
only C and C because they are products in the overall reaction
only A because it is the reactant in the rate-determining step
O only E and B because they are the reactants in the rate-determining step
The rate law depends on only A because it is the reactant in the rate-determining step.
What is the rate law;The rate law is a representation of the rate of reaction. The fast reaction is E+B ------> A+ D. The slow reaction is A + A ----->C + E. The overall reaction is A + B ------> C + D.
We know that the rate law depends only on the the slow reaction hence the rate law depends on only A because it is the reactant in the rate-determining step.
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The "iodine clock reaction" is a popular chemical demonstration. As part of that demonstration, the I−3 ion is generated in the reaction
S2O2−8(aq)+3I−(aq)⟶2SO2−4(aq)+I−3(aq)
In one trial, the unique rate of reaction was 6.93 μmol⋅L−1⋅s−1. What was the rate of reaction of iodide ions?
1. Initial Rate = _______ μmol⋅L−1⋅s−1 ??????
What was the rate of formation of sulfate ions?
2. Rate of formation = _______ μmol⋅L−1⋅s−1 ??????
In one trial, the unique rate of reaction was 6.93 μmol⋅L−1⋅s−1, the initial rate is 17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex] and rate of formation of sulfate ions was 11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
What is the rate of recation?Reaction rate, in chemistry, is the speed at which a chemical reaction proceeds.
[tex](S_2O_8)^-^2 (aq) + 3 I^-(aq)[/tex] → [tex]2 S0_4^-^2 (aq) + 3I^- (aq)[/tex]
Rate of the reaction = -Δ [[tex]S_20_8^-^2[/tex]] /Δ t = -1/3 Δ [[tex]I^-[/tex]] /Δ t
5.8 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex] = -1/3 Δ [[tex]I^-[/tex]] /Δ t
-Δ [[tex]I^-[/tex]] /Δ t =17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
So the rate of reaction of iodide ion =17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
+1/2Δ [[tex]S0_4^-^2[/tex]] /Δ t = rate of reaction
+1/2Δ [[tex]S0_4^-^2[/tex]] /Δ t = 5.8 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
+ Δ [[tex]S0_4^-^2[/tex]] /Δ t = 5.8 X 2 = 11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
Rate of formation of sulfate ions=11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
Hence, the initial rate is 17.4 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex] and rate of formation of sulfate ions was 11.6 μmol⋅[tex]l^-^1[/tex]⋅[tex]s^-^1[/tex]
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Please show steps Thanks
Answer:
2.5M
Explanation:
First calculate the gram-formula mass of CaCO3 (add up the mass of each element in the compound)
40.1 + 12.01 + 16(3) = 100.11
Now use the mole calculation equation on Table T and plug in the numbers
(Keep in mind that 25 is the given mass)
25/100.11 = 2.497 or 2.5M
A gallon of paint covers 350 square feet.
How many gallons must be bought to cover a room with two 16’ by 10’ walls and two 14’ by 10’ walls?
Can somebody who know how to do this solve this for me?
Answer:
2,137... gallons
Explanation:
(160+140+14x16x2)/350=2,137...
What is the mass number of a single atom of magnesium-25?
Answer: It is approximately 24.985837
Jeff is chasing his brother running 12m/s.He speeds up to 21m/s over 15 seconds.What is the acceleration?
Answer:
a = 0.6 m/s² .
Explanation:
given that:
• Vi = 12m/s
• Vf = 21 m/s
• t = 15 s
• a = ?
∴ a = (Vf - Vi) / t
⇒ a = (21 - 12) / 15
⇒ a = 0.6 m/s² ...answer...
Note that:
▪ 'Vf' refers to final velocity
▪ 'Vi' refers to initial velocity
▪ 't' refers to time period
▪ 'a' refers to acceleration
hope that helps...
2. What is the concentration of hydrochloric acid?
Why do you think it is
important to group substances and mixtures based on their classifications or uses?
The purpose of classification is to identify objects with common or similar properties.
What is a mixture?A mixture is composed of one or more pure substances in varying compositions.
It's important for scientists to know the properties of matter because all things are made up of matter.
Each type of matter has different physical characteristics and scientists need to know and understand these characteristics to make calculations.
The main phases of matter are solid liquid and gas.
Hence, the purpose of classification is to identify objects with common or similar properties.
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Which statement best describes the role of oxygen in cellular respiration?
OA. Oxygen molecules are a waste product of electron flow.
B. Oxygen molecules form as ATP molecules are made.
OC. Oxygen molecules form as sugar molecules are broken down.
OD. Oxygen molecules are used to make water molecules.
The role of oxygen in cellular respiration is to make water molecules. hence, option (D) is correct.
What is Cellular respiration ?
Cellular respiration is the process in which cells break down molecules for energy.
The cells use oxygen to break down food in the form of glucose to produce water and release carbon dioxide.
During aerobic cellular respiration, glucose reacts with oxygen, forming ATP that can be used by the cell. Carbon dioxide and water are created as byproducts.
In this reaction, energy is produced in the form of ATP that is used by the cell for its various activities.
Thus the correct answer is option D.
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Convert 26.02 x 1023 molecules of C2H8 to grams. Round your answer to the hundredths place.
No of molecules=26.02×10²³molecules
No of moles
26.02×10²³/6.023×10²³4.3molMolar mass
C2H82(12)+8(1)24+832g/molMass
Moles×Molar mass32(4.3)137.6g[tex]\\ \tt{:}\longrightarrow No\:of\:moles=\dfrac{Molecules}{Avagadro\:no}[/tex]
[tex]\\ \tt{:}\longrightarrow No\:of\:moles=\dfrac{26.02\times 10^{23}}{6.023\times 10^{23}}[/tex]
[tex]\\ \tt{:}\longrightarrow No\:of\:moles=4.32mol[/tex]
Molar mass of Ethane=32g/molWe need the mass
[tex]\\ \tt{:}\longrightarrow No\:of\:moles\times molar\:mass[/tex]
[tex]\\ \tt{:}\longrightarrow 32(4.32)[/tex]
[tex]\\ \tt{:}\longrightarrow 138.24g[/tex]
A student prepares a solution of Potassium Nitrate (KNO3) containing 95g at 40 C. This solution is -
A.) Saturated
B.) Unsaturated
C.) Supersaturated
D.) None of the Above
From the solubility curve as shown, the solution of 95g at 40 C can be said to be unsaturated.
What is a saturated solution?The term saturated solution has to do with a solution which contains just as much solute as it can normally hold at a particular temperature.
Looking at the solubility curve as shown, the solution of 95g at 40 C can be said to be unsaturated.
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When water, oxygen, and iron
combine, what is produced?
A. rust
B. carbon
C. carbon dioxide
D. carbon monoxide
Answer:
When we combine oxygen, and iron rust is produce.
Explanation:
The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust. Iron and steel rust when they come into contact with water and oxygen – both are needed for rusting to occur.
What is the pH of a 0.034 M
solution hydroiodic acid (HI)?
pH = [?]
Answer:
1.47
Explanation:
acellus
What is the density of helium at 0.975 atm and 27.0 C?
Answer:
0.158g/L.
Explanation:
MM of helium gas or He =4 g/mol
P = 0.974 atm
T = 27 °C, but we need absolute temperature.
TK = TC + 273
T = 27 + 273 = 300 K
m/V = (4 g/mol · 0.975 atm) / (0.0821 L·atm/mol·K · 300 K)
m/V = 0.975/6.1575 g/L
m/V = 0.158g/L
Answer: The density of the helium is 0.158g/L.
ASAP 100 POINTS Which molecules carries instructions for inherited traits
A.DNA
B CARbohydrate
C.Protein
D.Lipid
Answer:
A.DNA
Explanation:
Ahaa Its gona be right
Answer:
D.N.A.
Explanation:
Hi student! Let me help you out on this question.
D.N.A. is the molecule which carries instructions for inherited traits.
[tex]\therefore,Option\quad A \quad is \quad correct[/tex]
Hope that this helped! have a good day ahead.
100
Cut a 7-inch-diameter circle out of cardstock. Draw a spiral on the circle as shown. Next, use the scissors to cut along the lines you drew starting on the outside and ending in the center. Use the hole punch or scissors to make a hole at the middle of the spiral and attach the thread with a knot. Tie the other end of the thread loosely around the center of the stick so you can suspend the spiral in the air. Fill the pot with 2 inches of water. Heat the water until it boils, and then turn off the heat source. Let the pot sit for 4 minutes. Holding the ends of the stick with the spiral attached, position the bottom of the spiral right above the top of the pot so it’s not touching the water. Describe what happens.
Enter your answer to Part A here:
The heat will go up right above the top of the pot and then will go through the hole in the centre.
What is heat?Heat is the transfer of kinetic energy from one medium or object to another, or from an energy source to a medium or object.
Conduction is probably the most basic and intuitive way of achieving heat transfer. Something hot touches something cool and the cool thing heats up. For instance, the water in a pot boils when the flame from the stovetop heats the pan, and the heat from the pan is transferred to the water via conduction.
Thus, the heat will go up right above the top of the pot and then will go through the hole in the centre.
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How many grams of CO2 are produced if 2.09 moles of hydrochloric acid are reacted with
calcium carbonate?
Answer:
The molar mass of CO2 = 44.01 g/mol
Explanation:
Start with 2.09 moles of HCl and convert to moles of CO2 For every 2 moles of HCl used, 1 mole of CO2 is formed.
2.09 mol HCl •(1 mol CO2/2 mol HCl) = 1.045 mol CO2
Now convert moles of CO2 to grams using the molar mass.
1.045 mol CO2 • 44.01 g/mol = 45.99 grams CO2
3 significant figures = 46.0 grams CO2
Hope This Helped
How much energy is wasted by a 10% efficient filament bulb with 5 J of input?
Answer:
4.5 J wasted
Explanation:
10 % efficient means 90% wasted
90% of 5 J = .9 *5 = 4.5 J
Helium occupies 293 mL at 788 Torr and 25C. If the sample is condensed into a 0.115 liter flask, what will the new pressure be, assuming constant temperature?
Answer:
=2007.69 Torr
Explanation:
The new pressure of helium gas assuming constant temperature is equal to 2007.69
Torr.
Given the following data:
Initial volume = 293 mL
Final volume = 0.115 L
Initial pressure = 788 Torr
Temperature = 25°C.
Conversion:
Initial volume = 293 mL to L = 293/1000=0.293L
To determine the new pressure assuming constant temperature, we would apply Boyle's law:
Mathematically, Boyle's law is given by the formula;
PV=K
P1V1=P2V2
Where;
P1 is the original (initial) pressure.
P2 is the final pressure.
V1 is the original (initial) volume.
V2 is the final volume.
Substituting the given parameters into the formula, we have;
788×0.293 = P2 × 0.115
230.884 = 0.115P2
P2 = 230.884/0.115
P2 =2007.69
A certain atom has 22 protons and 19 electrons. This atom loses an electron. The net charge on the atom is now 4+. If this same atom with 22 protons and 19 electrons were to gain 3 electrons, the net charge on the atom would be
Answer: 0
Explanation:
If 3 electrons were to be gained, then the number of protons would equal the number of electrons.
A piece of unknown solid substance weighs 44.7 grams and requires 2110 J to increase its temperature from 23.2 C to 89.6 C. What is the specific heat of the substance?
Answer:
silicon 0.712 J/g°C
Explanation:
i hope this helps you, sorry if im wrong, but this should be correct!
Answer:
.7109 j / gm-C
Explanation:
Specific heat = j/gm-C
j = 2110 gm = 44.7 C = ( 89.6-23.2) = 66.4
2110 /(44.7 * 66.4) = .7109 j/gm-C
2.70 L of a gas has a pressure of 0.63 atm. What is the volume of the gas at 105kPa?
[tex]\huge{\green}\fcolorbox{blue}{black}{\bf{\underline{\red{\color{brown}Answer}}}}[/tex]
4.44l
Explanation:
[tex] \sf Volume \: of \: gas \: before(V_1) = 2.7 \: l \\ \sf Pressure \: of \: gas \: before(P_1) = 0.63 \: atm \\ \sf 0.63 \times 101.3 = 63.8 \: kPa \\ \sf Volume \: of \: gas \: after(V_2) = ? \\ \sf Pressure \: of \: gas \: after( P_2) = 105 \: kPa[/tex]
[tex] \textsf{ By using Boyle's law} \\ \\ \tt{ \frac{P_1}{V_1} = \frac{P_2}{V_2} }[/tex]
[tex] \sf \longrightarrow \frac{2.70}{63.8} = \frac{V_2}{105} \\ \\ \\ \sf \longrightarrow \frac{2.7 \times 105}{63.8} = V_2 \\ \\ \\ \sf \longrightarrow \frac{283.5}{63.8} = V_2 \\ \\ \\ {\orange {\boxed{ \longrightarrow 4.44 \: l = V_2}}}[/tex]
The diagram shows the potential energy changes for a reaction pathway. (10 points)
A curved lined graph is shown. The y axis of the graph has the title Potential Energy. The x axis of the graph has the title Reaction Pathway. The graph curve begins at a higher level and ends at a slightly lower level. A vertical line labeled A, starting from the x axis till the beginning of the graph line is shown. A vertical line labeled B, starting from the x axis till the uppermost hump in the graph curve is shown. Another vertical line labeled C is shown from starting from the x axis till the point where the graph curve ends.
Part 1: Does the diagram illustrate an endothermic or an exothermic reaction? Give reasons in support of your answer.
Part 2: Describe how you can determine the total change in enthalpy and activation energy from the diagram and if each is positive or negative.
1) The diagram shows an exothermic reaction since the potential energy of the products is less than that of the reactants, meaning energy was released.
2) To find the change in enthalpy, determine the difference between the potential energy of the products and the potential energy of the reactants. (on this diagram, C-A) To find the activation energy, find the difference between the potential energy of the reactants and the "peak" of the curve (on this diagram, B-A). For this diagram, both the enthalpy and activation energy are positive.
Answer:
Part 1 and Part 2 Answer
Explanation:
Part 1:
The reactions have higher potential energy than the products, this means it is an exothermic reaction.
Part 2:
Change in enthalpy is determined by the difference between potential energy of the reactants (A) and potential energy of the products (C). Because the reactants is higher than the products' and we know the reaction is exothermic, the change in enthalpy will be negative (-∆H).
The activation energy can be determined by the difference between the peak of the graph (B) and the potential energy of reactants (A). The activation energy would be positive.
Convert 7.50 mol of Li₂O to grams
Answer:
223.5 g
Explanation:
The formula between the number of moles, mass and Mr can be used to convert moles to grams.
Number of moles = mass ÷ Mr
So, mass = number of moles × Mr
Mr of Li₂O = (6.9 × 2) + 16 = 29.8
∴ Mass = 7.5 × 29.8 = 223.5 g
does a displacement reaction take place in iron + sodium chloride? and if so why?
Answer:
No.
A more reactive metal displaces or pushes out a less reactive metal from its compound. In the reactivity series, sodium is more reactive than iron hence no displacement reaction will occur.
Analyze the word problem and match the vocabulary terms to the chemicals in the word problem.
5.00 grams of solid citric acid is dissolved in 500.00 ml of water to make aqueous citric acid
5.00 grams of solid citric acid (solute) is dissolved in 500.00 ml of water (solvent) to make aqueous citric acid (solution).
What is a solution?A solution is a homogeneous mixture prepared by dissolving a solute in a solvent.
5.00 grams of solid citric acid is dissolved in 500.00 ml of water to make aqueous citric acid.
In this example:
5.00 grams of solid citric acid is the solute (what is dissolved).500.00 ml of water is the solvent (the media in which the solute is dissolved).Aqueous citric acid is the resulting solution.5.00 grams of solid citric acid (solute) is dissolved in 500.00 ml of water (solvent) to make aqueous citric acid (solution).
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A flask with a volume of 250.0 mL contains air with a density of 1.164 g/L. What is the mass of the air contained in the flask?
Answer:
convert 250.0 mL in Liters :250. 0 / 1000 = 0,25 LDensity = 1.240 g/LMass
Explanation:
A 2% sucrose solution is isotonic with 1.5% solution of an unknown substance. Calculate molecular mass of unknown substance.
The molar mass of the unknown substance is 256.6 g/mol.
What is the molar mass of sucrose?The molar mass of sucrose C12H22011 is 342 g/mol.
A 2% sucrose solution is isotonic with 1.5% solution of an unknown substance.
Molar mass of sucrose = Molar mass of unknown substance.
2% × 1000/342 = 1.5% × 1000/x
x = 342 × 1.5/2
x = 256.5 g/ mol
Therefore, the molar mass of the unknown substance is 256.6 g/mol.
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