Question 1

Which of the following statements best describes the difference between a physical change and a chemical change?

Accepted Answer

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

Question 2

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

Accepted Answer

$$\mathrm{CO_2$}$$

Question 3

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

Accepted Answer

The electrostatic attraction between oppositely charged ions is very strong.

Question 4

A 0.500 mol sample of NaCl is dissolved in enough water to make 1.00 L of solution. What is the molarity of the solution?

Accepted Answer

$$0.500\ \mathrm{M}$$

Question 5

Which of the following is the correct balanced equation for the reaction of aluminum with oxygen to form aluminum oxide?

Accepted Answer

$$4\mathrm{Al} + 3\mathrm{O}_2 \rightarrow 2\mathrm{Al}_2\mathrm{O}_3$$

Question 6

A student mixes solutions of silver nitrate and sodium chloride. A white precipitate forms. Which type of reaction has occurred?

Accepted Answer

Double displacement (precipitation)

Question 7

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 8

Which of the following best describes the VSEPR theory?

Accepted Answer

It explains the arrangement of atoms in a molecule based on the repulsion between electron pairs.

Question 9

A gas occupies 2.00 L at 1.00 atm and 300 K. What will be its volume at 2.00 atm and 300 K, assuming ideal gas behavior?

Accepted Answer

$$1.00\ \mathrm{L}$$

Question 10

Which of the following intermolecular forces is the strongest in water ($$\mathrm{H_2O}$$)?

Accepted Answer

Hydrogen bonding

Question 11

Which of the following is a correct statement about the kinetic molecular theory of gases?

Accepted Answer

Gas particles are in constant, random motion and collisions are perfectly elastic.

Question 12

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

Accepted Answer

Ice is less dense than liquid water because its molecules form an open hexagonal structure.

Question 13

A 25.0 mL sample of 0.200 M HCl is titrated with 0.100 M NaOH. What volume of NaOH is required to reach the equivalence point?

Accepted Answer

$$50.0\ \mathrm{mL}$$

Question 14

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 15

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electron pairs between atoms.

Question 16

Which of the following is a correct net ionic equation for the reaction between aqueous solutions of Na$$_2SO$_4$$ and BaCl$$_2$$?

Accepted Answer

$$\mathrm{Ba$$^{2+}$$(aq) + SO_4$^{2-}(aq) \rightarrow $$BaSO_4$$(s)}$$

Question 17

Which of the following statements about atomic structure is correct?

Accepted Answer

Protons and neutrons are found in the nucleus, while electrons are found in orbitals around the nucleus.

Question 18

A sample of gas is collected over water at 25°C. The total pressure is 755 mmHg, and the vapor pressure of water at 25°C is 23.8 mmHg. What is the partial pressure of the dry gas?

Accepted Answer

$$731.2\ \mathrm{mmHg}$$

Question 19

Which of the following best explains the trend in atomic radius across a period in the periodic table?

Accepted Answer

Atomic radius decreases from left to right due to increasing nuclear charge pulling electrons closer.

Question 20

Which of the following is the correct formula for calculating the percent composition by mass of an element in a compound?

Accepted Answer

$$\frac{	ext{mass of element in 1 mol of compound}}{	ext{molar mass of compound}} 	imes 100\%$$

CHEM 1201 General Chemistry I Syllabus and Chapter Overview

Guida di studio - Domande di pratica

Study guide - Flashcard