Question 1

Which of the following best describes a compound?

Accepted Answer

A substance composed of two or more elements chemically bonded in fixed proportions.

Question 2

Which of the following is a physical property?

Accepted Answer

Melting point.

Question 3

A student measures the mass of a sample as 2.50 g and its volume as 1.25 mL. What is the density of the sample?

Accepted Answer

$$2.00\ \mathrm{g/mL}$$

Question 4

Which of the following is the correct scientific notation for 0.00056?

Accepted Answer

$$5.6 	imes 10$$^{-4}$$

Question 5

Which statement about isotopes is correct?

Accepted Answer

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

Question 6

Which element is most likely to form a cation?

Accepted Answer

Sodium (Na)

Question 7

What is the correct formula for calcium chloride?

Accepted Answer

$$\mathrm{$$CaCl_2$$}$$

Question 8

Which of the following best describes an ionic bond?

Accepted Answer

Transfer of electrons from a metal to a nonmetal.

Question 9

A molecule contains 2 hydrogen atoms and 1 oxygen atom. What is its chemical formula?

Accepted Answer

$$\mathrm{H_2O}$$

Question 10

What is the percent composition by mass of oxygen in water ($$\mathrm{H_2O}$$)? (Atomic masses: H = 1, O = 16)

Accepted Answer

$$88.9\%$$

Question 11

Which of the following is a double replacement reaction?

Accepted Answer

$$\mathrm{$$AgNO_3$$ + NaCl \rightarrow AgCl + $$NaNO_3$$}$$

Question 12

Balance the following equation: $$\mathrm{C_2H_6 + O_2$ \rightarrow CO_2$ + H_2O}$$

Accepted Answer

$$2\mathrm{C_2H_6} + 7\mathrm{O_2$} \rightarrow 4\mathrm{CO_2$} + 6\mathrm{H_2O}$$

Question 13

If 4.0 g of hydrogen reacts with excess oxygen to form water, how many grams of water are produced? ($$\mathrm{2H_2 + O_2$ \rightarrow 2H_2O}$$; H = 1, O = 16)

Accepted Answer

$$36.0\ \mathrm{g}$$

Question 14

Which of the following is the limiting reactant when 10.0 g of nitrogen reacts with 10.0 g of hydrogen to form ammonia ($$\mathrm{N_2$ + 3H_2 \rightarrow 2NH_3}$$)? (N = 14, H = 1)

Accepted Answer

Hydrogen

Question 15

Which of the following is a property of gases according to the ideal gas law?

Accepted Answer

Gases expand to fill their container.

Question 16

What is the molarity of a solution containing 0.5 mol of NaCl dissolved in 2.0 L of water?

Accepted Answer

$$0.25\ \mathrm{M}$$

Question 17

Which of the following solutions is most acidic?

Accepted Answer

pH = 2

Question 18

Which of the following is a safety precaution that should always be followed in the chemistry lab?

Accepted Answer

Always wear proper lab safety equipment.

Question 19

Which of the following is a real-world application of chemistry?

Accepted Answer

Studying the composition of food.

Introduction to Chemistry: Core Concepts and Principles

Guida di studio - Domande di pratica

Study guide - Flashcard