Question 1

Which of the following best describes the difference between a compound and a mixture?

Accepted Answer

A compound has a fixed composition with elements in definite proportions, while a mixture does not.

Question 2

Which law states that mass is neither created nor destroyed in a chemical reaction?

Accepted Answer

Law of Conservation of Mass

Question 3

A sample contains 12.0 g of carbon and 32.0 g of oxygen. What is the empirical formula of the compound formed?

Accepted Answer

$$\mathrm{CO_2$}$$

Question 4

Which of the following is a chemical property?

Accepted Answer

Reactivity with acid

Question 5

Which of the following best explains why water is considered a polar molecule?

Accepted Answer

It has a bent molecular shape and unequal sharing of electrons.

Question 6

A student mixes hydrochloric acid ($$\mathrm{HCl}) $$with sodium hydroxide ($$\mathrm{NaOH}). $$Which type of reaction occurs?

Accepted Answer

Neutralization

Question 7

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 8

Which of the following statements about the periodic table is correct?

Accepted Answer

Elements in the same group have the same number of valence electrons.

Question 9

A balloon filled with helium gas at 1.0 atm and 300 K has a volume of 2.0 L. If the temperature increases to 600 K at constant pressure, what is the new volume?

Accepted Answer

$$4.0\ \mathrm{L}$$

Question 10

Which of the following best describes an oxidation-reduction (redox) reaction?

Accepted Answer

A reaction in which electrons are transferred between species.

Question 11

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

Accepted Answer

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

Question 12

A solution contains $$0.5$$ moles of $$\mathrm{NaCl}$$ dissolved in $$1.0 L of $$water. What is the molarity of the solution?

Accepted Answer

$$0.5\ \mathrm{M}$$

Question 13

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

Accepted Answer

They have strong electrostatic attractions between oppositely charged ions.

Question 14

Which of the following is a correct statement about acids and bases according to the Bronsted-Lowry theory?

Accepted Answer

An acid is a substance that donates a proton ($$\mathrm{H^+}).$$

Question 15

A patient is given a saline solution intravenously. Why is it important that the solution is isotonic with blood?

Accepted Answer

To ensure that red blood cells do not shrink or burst due to osmosis.

Question 16

Which of the following is the correct net ionic equation for the reaction between silver nitrate ($$\mathrm{$$AgNO_3$$}) $$and sodium chloride ($$\mathrm{NaCl}) in $$aqueous solution?

Accepted Answer

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

Question 17

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

Accepted Answer

It lowers the activation energy, increasing the reaction rate.

Question 18

A sample of gas occupies $$5.0\ \mathrm{L} at$$ $$2.0\ \mathrm{atm}. If $$the pressure is decreased to $$1.0\ \mathrm{atm} at $$constant temperature, what is the new volume?

Accepted Answer

$$10.0\ \mathrm{L}$$

Question 19

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

Accepted Answer

O=C=O

Question 20

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

Accepted Answer

Hydrogen bonding causes ice to have an open, hexagonal structure.

Introductory Chemistry: Course Schedule and Chapter Overview

Guida di studio - Domande di pratica

Study guide - Flashcard