$$\text{pH} = -\log_{10} [H^+]$$

$$M = \frac{\text{moles of solute}}{\text{liters of solution}}$$

$$\text{Percent composition} = \frac{\text{mass of element}}{\text{total mass of compound}} \times 100$$

Question 1

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

Accepted Answer

A process for making observations, forming hypotheses, conducting experiments, and analyzing results.

Question 2

A student measures the mass of a sample as 12.5 g and its volume as 5.0 mL. What is the density of the sample?

Accepted Answer

2.5 g/mL

Question 3

Which equation correctly relates pressure, volume, number of moles, and temperature for an ideal gas?

Accepted Answer

$$P V = n R T$$

Question 4

Which of the following is a real-world example of an oxidation-reduction reaction?

Accepted Answer

The rusting of iron in moist air.

Question 5

A buffer solution is important in biological systems because it:

Accepted Answer

Maintains a constant pH despite addition of acids or bases.

Question 6

Which formula is used to calculate the pH of a solution given its hydrogen ion concentration?

Accepted Answer

$$	ext{pH} = -\log_{10} [H^+]$$

Question 7

Which of the following statements about acids and bases is correct?

Accepted Answer

Bases decrease the concentration of $$H^+$$ ions in solution.

Question 8

A patient receives a radioactive isotope for medical imaging. Which principle of nuclear radiation is most relevant to this application?

Accepted Answer

The isotope emits radiation that can be detected externally.

Question 9

Which equation is used to calculate the molarity ($$M) of a $$solution?

Accepted Answer

$$M = \frac{	ext{moles of solute}}{	ext{liters of solution}}$$

Question 10

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electrons between atoms.

Question 11

A chemical reaction produces 0.5 moles of water from 1 mole of hydrogen and 0.5 moles of oxygen. Which type of reaction is this?

Accepted Answer

Combination reaction

Question 12

Which equation is used to relate energy ($$E) $$and mass ($$m) in $$nuclear reactions?

Accepted Answer

$$E = m c^2$

Question 13

Which of the following is an example of a buffer in the human body?

Accepted Answer

Bicarbonate system in blood

Question 14

Which equation is used to calculate the percent composition of an element in a compound?

Accepted Answer

$$	ext{Percent composition} = \frac{	ext{mass of element}}{	ext{total mass of compound}} 	imes 100$$

Question 15

Which of the following is a property of salts?

Accepted Answer

They are formed from the reaction of an acid and a base.

Question 16

Which equation is used to calculate the number of moles ($$n) $$from mass ($$m) $$and molar mass ($$M$$)?

Accepted Answer

$$n = \frac{m}{M}$$

Question 17

Which of the following is a consequence of exposure to ionizing radiation?

Accepted Answer

Damage to cellular DNA

Question 18

A student mixes 50 mL of 0.2 M NaCl with 50 mL of 0.4 M NaCl. What is the final concentration of NaCl in the mixture?

Accepted Answer

0.3 M

Question 19

Which of the following is a characteristic of a chemical reaction at equilibrium?

Accepted Answer

The rates of the forward and reverse reactions are equal.

CHEM 1306 Introductory Chemistry I Syllabus Study Guide

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