Q: Which of the following is the correct formula for calculating the heat ($$q) $$absorbed or released by a substance?

$$q = m \times c \times \Delta T$$

Q: Which of the following is the correct formula for calculating the molarity ($$M) of a $$solution?

$$M = \frac{\text{moles of solute}}{\text{liters of solution}}$$

Question 1

Which of the following best describes an example of a chemical change?

Accepted Answer

Burning a piece of paper

Question 2

A student measures the mass of a sample three times and records 12.34 g, 12.35 g, and 12.33 g. The true mass is 12.80 g. Which statement best describes the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following is the correct balanced equation for the combustion of methane ($$\mathrm{CH_4$}) in $$oxygen?

Accepted Answer

$$\mathrm{CH_4$} + 2\mathrm{O_2$} \rightarrow \mathrm{CO_2$} + 2\mathrm{H_2O}$$

Question 4

Which of the following statements about buffers is correct?

Accepted Answer

Buffers resist changes in pH when small amounts of acid or base are added.

Question 5

A solution has a pH of 3. What is the concentration of $$\mathrm{H^+}$$ ions in the solution?

Accepted Answer

$$1 	imes 10$$^{-3}$$ M

Question 6

Which of the following best describes the difference between an ionic and a covalent bond?

Accepted Answer

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons.

Question 7

A sample of gas occupies 2.0 L at 1.0 atm and 300 K. What will be its volume at 2.0 atm and 300 K? (Assume ideal gas behavior.)

Accepted Answer

1.0 L

Question 8

Which of the following is a correct Lewis structure for carbon dioxide ($$\mathrm{CO_2$}$$)?

Accepted Answer

O=C=O

Question 9

Which of the following is the correct formula for calculating the heat ($$q) $$absorbed or released by a substance?

Accepted Answer

$$q = m 	imes c 	imes \Delta T$$

Question 10

Which of the following is a correct application of the law of conservation of mass?

Accepted Answer

The total mass of reactants equals the total mass of products in a chemical reaction.

Question 11

Which of the following is the correct number of significant figures in the measurement 0.004560 g?

Accepted Answer

4

Question 12

A buffer solution is prepared by mixing acetic acid ($$\mathrm{CH_3COOH}) $$and sodium acetate ($$\mathrm{CH_3COONa}). $$What happens to the pH if a small amount of HCl is added?

Accepted Answer

The pH decreases slightly.

Question 13

Which of the following is a physical property?

Accepted Answer

Boiling point

Question 14

Which of the following best describes the role of a catalyst in a chemical reaction?

Accepted Answer

It speeds up the reaction without being consumed.

Question 15

Which of the following is the correct formula for calculating the molarity ($$M) of a $$solution?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Question 16

A patient receives 500 mL of a 0.9% NaCl solution intravenously. What is the mass of NaCl delivered? (0.9% means 0.9 g NaCl per 100 mL solution)

Accepted Answer

4.5 g

Question 17

Which of the following is the correct electron configuration for a neutral sodium atom ($$\mathrm{Na}$$, atomic number 11)?

Accepted Answer

$$1s^2$$ $$2s^2$$ $$2p^6$$ $$3s^1$$

Question 18

Which of the following best describes the effect of increasing temperature on the rate of a chemical reaction?

Accepted Answer

The rate increases because more molecules have enough energy to react.

Question 19

Which of the following is a correct statement about isotopes?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 20

Which of the following is the correct formula for calculating percent composition by mass?

Accepted Answer

$$\frac{	ext{mass of element}}{	ext{total mass of compound}} 	imes 100\%$$

Comprehensive Study Guide for General Chemistry Final Exam and Lab Practicum

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