Q: A student titrates 0.0500 L of acetic acid with 0.100 M NaOH. If the equivalence point is reached after adding 0.0250 L of NaOH, what is the molarity of the acetic acid solution?

$$M_1$$ = \frac{0.100 \times 0.0250}{0.0500} = 0.0500\ \mathrm{M}$$

Q: A copper content test is performed by dissolving 2.98 g of CuSO4·5H2O (MM = 249.7 g/mol) in water to make 500.0 mL of solution. What is the molarity of CuSO4·5H2O in the solution?

$$\mathrm{M = \frac{2.98}{249.7 \times 0.5000} = 0.0238\ \mathrm{M}}$$

Q: During a Boyle's law experiment, a student collects the following data: Pressure = 1.20 atm, Volume = 0.83 L. What is the value of $$P \times V$$ for this trial?

$$1.20 \times 0.83 = 0.996\ \mathrm{atm \cdot L}$$

Question 1

Which of the following is the correct balanced net ionic equation for the reaction between BaCl2(aq) and CuSO4(aq)?

Accepted Answer

$$\mathrm{Ba$$^{2+}$$(aq) + SO_4$^{2-}(aq) \rightarrow $$BaSO_4$$(s)}$$

Question 2

A student titrates 0.0500 L of acetic acid with 0.100 M NaOH. If the equivalence point is reached after adding 0.0250 L of NaOH, what is the molarity of the acetic acid solution?

Accepted Answer

$$M_1$$ = \frac{0.100 	imes 0.0250}{0.0500} = 0.0500\ \mathrm{M}$$

Question 3

When using a burette to titrate a solution, which of the following best describes how to read the volume?

Accepted Answer

Read the volume at the bottom of the meniscus at eye level.

Question 4

A student is asked to calculate the molarity of a NaOH solution using KHP (MM = 204.2 g/mol). If 0.500 g of KHP is titrated with 25.00 mL of NaOH, what is the molarity of the NaOH solution?

Accepted Answer

$$\mathrm{M = \frac{mol\ KHP}{L\ NaOH}} = \frac{0.500/204.2}{0.02500} = 0.0980\ \mathrm{M}$$

Question 5

Which piece of laboratory equipment is best suited for measuring 10.00 mL of a liquid with the highest precision?

Accepted Answer

Volumetric pipette

Question 6

A student records the following burette readings: Initial = 10.74 mL, Final = 27.86 mL. What is the volume of titrant delivered?

Accepted Answer

$$27.86\ \mathrm{mL} - 10.74\ \mathrm{mL} = 17.12\ \mathrm{mL}$$

Question 7

Which of the following statements about significant figures is correct when multiplying two measured values?

Accepted Answer

The result should have the same number of significant figures as the value with the fewest significant figures.

Question 8

A copper content test is performed by dissolving 2.98 g of CuSO4·5H2O (MM = 249.7 g/mol) in water to make 500.0 mL of solution. What is the molarity of CuSO4·5H2O in the solution?

Accepted Answer

$$\mathrm{M = \frac{2.98}{249.7 	imes 0.5000} = 0.0238\ \mathrm{M}}$$

Question 9

During a Boyle's law experiment, a student collects the following data: Pressure = 1.20 atm, Volume = 0.83 L. What is the value of $$P 	imes V$$ for this trial?

Accepted Answer

$$1.20 	imes 0.83 = 0.996\ \mathrm{atm \cdot L}$$

Question 10

If a student accidentally leaves the flask open during a massing experiment, what is the most likely effect on the calculated mass of copper in the sample?

Accepted Answer

The calculated mass will be lower than the true value.

Question 11

Which of the following is the correct net ionic equation for the reaction between CaCl2(aq) and Na2CO3(aq)?

Accepted Answer

$$\mathrm{Ca$$^{2+}$$(aq) + CO_3$^{2-}(aq) \rightarrow $$CaCO_3$$(s)}$$

Question 12

A student measures the absorbance of a solution and finds it to be 0.482 at 1.00 cm path length. If the molar absorptivity is $$1.50 	imes 10^3$\ \mathrm{L\ $$mol^{-1}$$\ cm$$^{-1}$$}$$, what is the concentration of the solution?

Accepted Answer

$$A = \varepsilon c l \Rightarrow c = \frac{A}{\varepsilon l} = \frac{0.482}{1.50 	imes 10^3$ 	imes 1.00} = 3.21 	imes 10$$^{-4}$$\ \mathrm{mol/L}$$

Question 13

Which of the following best describes the effect of increasing temperature on the solubility of most solid salts in water?

Accepted Answer

Solubility increases as temperature increases.

Question 14

In a calorimetry experiment, a student mixes 50.0 mL of 1.00 M HCl with 50.0 mL of 1.00 M NaOH. The temperature rises by 6.5°C. If the specific heat capacity of the solution is $$4.18\ \mathrm{J\ g$$^{-1}$$\ ^\circ C$$^{-1}$$}$$ and the density is $$1.00\ \mathrm{g\ mL$$^{-1}$$}$$, what is the heat evolved?

Accepted Answer

$$q = m c \Delta T = 100.0 	imes 4.18 	imes 6.5 = 2,717\ \mathrm{J}$$

Question 15

Which of the following is a correct statement regarding the use of personal protective equipment (PPE) in the laboratory?

Accepted Answer

PPE should be worn at all times when working with chemicals.

Question 16

A student is investigating Charles's law and collects the following data: Volume = 50.0 mL at 273 K, Volume = 75.0 mL at 373 K. What is the value of the constant $$\frac{V}{T}$$ for each trial?

Accepted Answer

$$\frac{50.0}{273} = 0.183\ \mathrm{mL/K}$$ and $$\frac{75.0}{373} = 0.201\ \mathrm{mL/K}$$

Question 17

Which of the following is the correct procedure for disposing of chemical waste in the laboratory?

Accepted Answer

Dispose of chemical waste in designated containers according to safety guidelines.

Question 18

A student is asked to identify the cation in a solution using flame tests. The solution produces a green flame. Which cation is most likely present?

Accepted Answer

Copper(II)

General Chemistry Lab Exam II Review: Safety, Equipment, Calculations, and Experimental Analysis

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