Question 1

Which of the following best describes the scientific method as used in chemistry?

Accepted Answer

A systematic process involving observation, hypothesis formation, experimentation, and conclusion.

Question 2

A student measures the mass of a sample as 12.5 grams and its volume as 5.0 mL. What is the density of the sample in $$\mathrm{g/mL}$$?

Accepted Answer

$$2.5\ \mathrm{g/mL}$$

Question 3

Which of the following is an example of a chemical change?

Accepted Answer

Iron rusting in moist air

Question 4

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 5

A compound contains 40% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of the compound?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 6

Which of the following best explains why ionic compounds tend to have high melting points?

Accepted Answer

Strong electrostatic forces between oppositely charged ions require a large amount of energy to break.

Question 7

A sample of gas occupies $$2.0\ \mathrm{L} at$$ $$1.0\ \mathrm{atm}$$ and $$300\ \mathrm{K}. If $$the pressure is increased to $$2.0\ \mathrm{atm}$$ and the temperature is raised to $$600\ \mathrm{K}$$, what is the new volume of the gas? (Assume ideal gas behavior.)

Accepted Answer

$$4.0\ \mathrm{L}$$

Question 8

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

Accepted Answer

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

Question 9

Which of the following best describes Le Chatelier's Principle?

Accepted Answer

If a system at equilibrium is disturbed, the system will shift to counteract the disturbance and restore equilibrium.

Question 10

A solution is prepared by dissolving $$10.0\ \mathrm{g} of $$NaCl in enough water to make $$500.0\ \mathrm{mL} of $$solution. What is the molarity of the solution? ($$\mathrm{Molar\ mass\ of\ NaCl} = 58.44\ \mathrm{g/mol})$$

Accepted Answer

$$0.342\ \mathrm{M}$$

Question 11

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 12

Which of the following best explains why water is a liquid at room temperature while methane ($$\mathrm{CH_4$}) is a $$gas?

Accepted Answer

Water molecules form hydrogen bonds, which are much stronger than the London dispersion forces in methane.

Question 13

A student is asked to convert $$25.0\ \mathrm{cm^3$} to$$ $$\mathrm{mL}. $$What is the correct answer?

Accepted Answer

$$25.0\ \mathrm{mL}$$

Question 14

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 15

A radioactive isotope decays with a half-life of 3 hours. If you start with $$80\ \mathrm{g}$$, how much remains after 9 hours?

Accepted Answer

$$10\ \mathrm{g}$$

Question 16

Which of the following is a correct statement about chemical equilibrium?

Accepted Answer

At equilibrium, the rates of the forward and reverse reactions are equal.

Question 17

A patient is given a saline solution that is $$0.90\%$$ NaCl by mass. If the patient receives $$500\ \mathrm{g} of $$this solution, how many grams of NaCl did they receive?

Accepted Answer

$$4.5\ \mathrm{g}$$

Question 18

Which of the following best describes a limiting reagent in a chemical reaction?

Accepted Answer

The reactant that is completely consumed first, limiting the amount of product formed.

Question 19

Which of the following is a correct statement about the metric system?

Accepted Answer

The prefix 'kilo-' means $$1000$$ times the base unit.

Question 20

Which of the following best explains why carbon forms four covalent bonds in most of its compounds?

Accepted Answer

Carbon has four valence electrons and needs four more to complete its octet.

Fundamental Chemistry (CHM 130) Syllabus and Course Overview

Guida di studio - Domande di pratica

Study guide - Flashcard