Question 1

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

Accepted Answer

An ionic bond involves the transfer of electrons from a metal to a nonmetal, while a covalent bond involves the sharing of electrons between two nonmetals.

Question 2

Which of the following is the correct formula for magnesium chloride?

Accepted Answer

$$\mathrm{$$MgCl_2$$}$$

Question 3

A patient is given 250 mL of a 0.9% NaCl solution intravenously. How many grams of NaCl are administered?

Accepted Answer

$$2.25\ \mathrm{g}$$

Question 4

Which of the following statements about water is TRUE?

Accepted Answer

Water has a bent molecular geometry due to the two lone pairs on oxygen.

Question 5

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

Accepted Answer

O=C=O

Question 6

What is the molarity of a solution prepared by dissolving 5.85 g of NaCl in enough water to make 500 mL of solution? (Molar mass of NaCl = 58.5 g/mol)

Accepted Answer

$$0.2\ \mathrm{M}$$

Question 7

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Ice is less dense than liquid water because hydrogen bonding causes the molecules to be more spread out in the solid state.

Question 8

Which of the following is the correct balanced equation for the reaction of hydrochloric acid with sodium hydroxide?

Accepted Answer

$$\mathrm{HCl} + \mathrm{NaOH} \rightarrow \mathrm{NaCl} + \mathrm{H_2O}$$

Question 9

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

Accepted Answer

$$1.0\ \mathrm{L}$$

Question 10

Which of the following is a property of acids?

Accepted Answer

They turn blue litmus paper red.

Question 11

Which of the following ions is most likely to form when calcium reacts with chlorine?

Accepted Answer

$$\mathrm{Ca$$^{2+}$$}$$

Question 12

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

Accepted Answer

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

Question 13

A solution has a pH of 3. Which of the following best describes the solution?

Accepted Answer

It is acidic.

Question 14

Which of the following is a correct statement about oxidation and reduction?

Accepted Answer

Oxidation is the loss of electrons, and reduction is the gain of electrons.

Question 15

Which of the following molecules is polar?

Accepted Answer

$$\mathrm{H_2O}$$

Question 16

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH_4$)_2SO_4}$$

Question 17

A buffer solution is prepared by mixing acetic acid and sodium acetate. Which of the following best describes the function of this buffer?

Accepted Answer

It maintains a relatively constant pH when small amounts of acid or base are added.

Question 18

Which of the following is the correct net ionic equation for the reaction between silver nitrate and sodium chloride?

Accepted Answer

$$\mathrm{Ag^+} + \mathrm{Cl^-} \rightarrow \mathrm{AgCl(s)}$$

Question 19

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

Accepted Answer

It increases the rate of the reaction by lowering the activation energy.

Question 20

A sample contains 0.5 moles of $$\mathrm{O_2$}. $$How many molecules of $$\mathrm{O_2$}$$ are present? ($$N_A = 6.02 	imes 10$$^{23}$$ molecules/mol)

Accepted Answer

$$3.01 	imes 10$$^{23}$$ molecules

GOB Chemistry: Key Concepts and Practice Questions

Guida di studio - Domande di pratica

Study guide - Flashcard