Q: Which of the following is the correct formula for calculating molarity?

$$\text{Molarity} = \frac{\text{amount of solute (mol)}}{\text{volume of solution (L)}}$$

Question 1

Which piece of laboratory glassware is most appropriate for preparing a solution of precise and known molarity, as shown in the first and sixth images?

Accepted Answer

Volumetric flask

Question 2

A student wants to prepare 250.0 mL of a 0.100 M NaCl solution. What mass of NaCl (molar mass = 58.44 g/mol) should be weighed out?

Accepted Answer

$$1.461\ 	ext{g}$$

Question 3

Which equation correctly relates the molarity and volume of a concentrated solution to that of a diluted solution?

Accepted Answer

$$M_1V_1 = M_2V_2$$

Question 4

A solution is prepared by diluting 10.0 mL of 2.00 M HCl to a final volume of 100.0 mL. What is the final concentration?

Accepted Answer

$$0.200\ 	ext{M}$$

Question 5

During a titration, 25.0 mL of 0.150 M NaOH is required to neutralize 30.0 mL of HCl. What is the concentration of the HCl solution?

Accepted Answer

$$0.125\ 	ext{M}$$

Question 6

Which of the following best describes a concentrated solution, as depicted in the second image?

Accepted Answer

A solution with a large amount of solute relative to solvent

Question 7

A student adds excess silver nitrate to 100.0 mL of a chloride solution and obtains 0.287 g of AgCl (molar mass = 143.32 g/mol). What is the molarity of Cl$$^- in $$the original solution?

Accepted Answer

$$0.0200\ 	ext{M}$$

Question 8

Which laboratory instrument, shown in the third image, is best used for measuring and transferring approximate volumes of liquid, but not for preparing solutions of precise molarity?

Accepted Answer

Graduated cylinder

Question 9

In a titration, what is the purpose of the indicator, as shown in the last two images?

Accepted Answer

To change color at the equivalence point

Question 10

A 50.0 mL sample of 0.200 M H$$_2SO$_4 is $$titrated with 0.100 M NaOH. What volume of NaOH is required to reach the equivalence point? (Balanced equation: $$H_2SO_4 + 2NaOH \rightarrow Na_2SO_4 + 2H_2O)$$

Accepted Answer

$$200\ 	ext{mL}$$

Question 11

Which of the following steps is NOT necessary when preparing a solution of known molarity, as shown in the sixth image?

Accepted Answer

Heating the solution to boiling

Question 12

A student needs to prepare 100.0 mL of 0.0500 M KNO$$_3$$ from a 0.500 M stock solution. What volume of stock solution should be used?

Accepted Answer

$$10.0\ 	ext{mL}$$

Question 13

Which of the following best describes the difference between a molecular equation and a net ionic equation?

Accepted Answer

A net ionic equation shows only the species that actually change during the reaction

Question 14

A 25.0 mL sample of 0.100 M Ba(OH)$$_2 is $$titrated with HCl. What volume of 0.200 M HCl is required to reach the equivalence point? (Balanced equation: $$Ba(OH)_2 + 2HCl \rightarrow $$BaCl_2$$ + 2H_2O)$$

Accepted Answer

$$50.0\ 	ext{mL}$$

Question 15

Which of the following is a correct statement about dilution?

Accepted Answer

The amount of solute remains constant during dilution

Question 16

A student uses a pipet (as shown in the eighth and ninth images) to transfer 10.00 mL of a stock solution into a 100.00 mL volumetric flask and dilutes to the mark. If the stock solution is 1.00 M, what is the concentration of the diluted solution?

Accepted Answer

$$0.100\ 	ext{M}$$

Question 17

Which of the following best describes the role of the volumetric flask in solution preparation?

Accepted Answer

It is used to measure a precise volume of solution

Question 18

In a gravimetric analysis, why is it important to add excess precipitating reagent?

Accepted Answer

To ensure all of the analyte reacts and precipitates

Question 19

Which of the following is the correct formula for calculating molarity?

Accepted Answer

$$	ext{Molarity} = \frac{	ext{amount of solute (mol)}}{	ext{volume of solution (L)}}$$

Aqueous Solutions: Molarity, Dilution, and Titration

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