Question 1

Which of the following statements best describes the difference between a physical change and a chemical change? Choose the most accurate answer.

Accepted Answer

A chemical change results in the formation of new substances with different properties, while a physical change does not alter the chemical identity.

Question 2

A sample of gas occupies $$2.50\ \mathrm{L} at$$ $$25\ ^\circ\mathrm{C}$$ and $$1.00\ \mathrm{atm}. If $$the temperature is increased to $$50\ ^\circ\mathrm{C} at $$constant pressure, what is the new volume? (Use the ideal gas law.)

Accepted Answer

$$2.71\ \mathrm{L}$$

Question 3

Which of the following is the correct electron configuration for a neutral atom of phosphorus ($$Z=15$$)?

Accepted Answer

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

Question 4

Which of the following compounds is most likely to be ionic?

Accepted Answer

$$\mathrm{NaCl}$$

Question 5

A solution is prepared by dissolving $$5.85\ \mathrm{g} of$$ $$\mathrm{NaCl} in $$enough water to make $$500.0\ \mathrm{mL} of $$solution. What is the molarity of the solution? ($$\mathrm{NaCl}$$ molar mass = $$58.5\ \mathrm{g/mol})$$

Accepted Answer

$$0.200\ \mathrm{M}$$

Question 6

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

Accepted Answer

Ice is less dense than liquid water due to hydrogen bonding creating an open hexagonal structure.

Question 7

Which of the following is the correct balanced equation for the combustion of methane ($$\mathrm{CH}_4$$)?

Accepted Answer

$$\mathrm{CH}_4 + 2\ \mathrm{O}_2 \rightarrow \mathrm{CO}_2 + 2\ \mathrm{H}_2\mathrm{O}$$

Question 8

Which of the following statements about acids and bases is correct according to the Brønsted-Lowry definition?

Accepted Answer

An acid is a proton donor and a base is a proton acceptor.

Question 9

A radioactive isotope decays with a half-life of $$10$$ years. If you start with $$80\ \mathrm{g}$$, how much remains after $$30$$ years?

Accepted Answer

$$10\ \mathrm{g}$$

Question 10

Which of the following best describes the octet rule?

Accepted Answer

Atoms tend to gain, lose, or share electrons to achieve eight electrons in their valence shell.

Question 11

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 12

A $$0.10\ \mathrm{M}$$ solution of acetic acid ($$\mathrm{CH}_3\mathrm{COOH}) $$has a $$[\mathrm{H}^+] of$$ $$1.3 	imes 10$$^{-3}$$\ \mathrm{M}. $$What is the pH of the solution?

Accepted Answer

$$2.89$$

Question 13

Which of the following is the correct formula for calculating the energy of a photon?

Accepted Answer

$$E = h 
u$$

Question 14

Which of the following is a correct Lewis structure for carbon dioxide ($$\mathrm{CO}_2$$)?

Accepted Answer

O=C=O, with each O atom having two lone pairs

Question 15

Which of the following statements about intermolecular forces is correct?

Accepted Answer

Hydrogen bonds are stronger than London dispersion forces.

Question 16

A sample of $$\mathrm{CaCO}_3$$ decomposes according to the equation: $$\mathrm{CaCO}_3 (s) \rightarrow \mathrm{CaO} (s) + \mathrm{CO}_2 (g). If$$ $$10.0\ \mathrm{g} of$$ $$\mathrm{CaCO}_3 is $$decomposed, how many grams of $$\mathrm{CO}_2$$ are produced? (Molar masses: $$\mathrm{CaCO}_3 = 100\ \mathrm{g/mol}$$, $$\mathrm{CO}_2 = 44\ \mathrm{g/mol})$$

Accepted Answer

$$4.4\ \mathrm{g}$$

Question 17

Which of the following is the correct net ionic equation for the reaction between aqueous solutions of $$\mathrm{NaCl}$$ and $$\mathrm{AgNO}_3$$?

Accepted Answer

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

Question 18

Which of the following best describes the difference between an endothermic and an exothermic reaction?

Accepted Answer

Endothermic reactions absorb heat, exothermic reactions release heat.

Question 19

Which of the following is the correct expression for the equilibrium constant $$K_c$$ for the reaction $$\mathrm{N}_2 (g) + 3\ \mathrm{H}_2 (g) \rightleftharpoons 2\ \mathrm{NH}_3 (g)$$?

Accepted Answer

$$K_c = \frac{[\mathrm{NH}_3]^2}{[\mathrm{N}_2][\mathrm{H}_2]^3}$$

Comprehensive Study Notes for Pearson Intro to Chemistry Chapters 1-10, 13

Guida di studio - Domande di pratica

Study guide - Flashcard