Question 1

Which of the following measurements contains the correct number of significant figures according to the zero rules: 0.00450 g?

Accepted Answer

3 significant figures

Question 2

A sample of water has a mass of 250.0 g and a volume of 250.0 mL. What is its density in $$\mathrm{g/mL}$$?

Accepted Answer

$$1.00\ \mathrm{g/mL}$$

Question 3

Convert $$25.0\ ^\circ\mathrm{C} to $$Kelvin.

Accepted Answer

$$298.2\ \mathrm{K}$$

Question 4

Which of the following is a heterogeneous mixture?

Accepted Answer

Salad with dressing

Question 5

Which of the following represents a chemical change?

Accepted Answer

Burning wood

Question 6

A gold bar has a mass of $$500.0\ \mathrm{g}$$ and a volume of $$25.9\ \mathrm{cm}^3. $$What is its density?

Accepted Answer

$$19.3\ \mathrm{g/cm}^3$$

Question 7

Which of the following is a pure compound?

Accepted Answer

Table salt ($$\mathrm{NaCl})$$

Question 8

Which of the following is the correct symbol for a beta particle?

Accepted Answer

$$^0_{-1}\mathrm{e}$$

Question 9

How many valence electrons does a chlorine atom have?

Accepted Answer

7

Question 10

Which of the following is an ionic compound?

Accepted Answer

$$\mathrm{NaCl}$$

Question 11

What is the molar mass of $$\mathrm{Ca(OH)_2}$$?

Accepted Answer

$$74.10\ \mathrm{g/mol}$$

Question 12

Which of the following molecules is polar?

Accepted Answer

$$\mathrm{H_2O}$$

Question 13

A radioactive isotope has a half-life of 3 days. If you start with 80 mg, how much remains after 9 days?

Accepted Answer

10 mg

Question 14

Which of the following best describes the relationship between density and specific gravity?

Accepted Answer

Specific gravity is the density of a substance divided by the density of water.

Question 15

Which of the following is the correct name for $$\mathrm{P_2O_5}$$?

Accepted Answer

Diphosphorus pentoxide

Question 16

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

Accepted Answer

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

Question 17

Which of the following best explains why the size or weight of a sample does not affect its density?

Accepted Answer

Density is a ratio of mass to volume, which remains constant for a pure substance.

Question 18

How many protons, neutrons, and electrons are in $$^{23}_{11}\mathrm{Na}$$?

Accepted Answer

11 protons, 12 neutrons, 11 electrons

Question 19

Which of the following best describes a covalent bond?

Accepted Answer

A bond formed by the sharing of electrons between two nonmetals

Question 20

How many moles are in 36.0 g of water ($$\mathrm{H_2O}$$)? ($$\mathrm{Molar\ mass\ of\ H_2O} = 18.0\ \mathrm{g/mol})$$

Accepted Answer

2.0 mol

General Chemistry Exam 1 Study Guide: Key Concepts and Skills

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