Q: A sample of gas has a density of $$1.25\ \mathrm{g/L} at$$ $$25.0\ ^\circ\mathrm{C}. $$What is the density in $$\mathrm{kg/m^3$}$$?

$$1.25\ \mathrm{kg/L} \times 1000\ \mathrm{L/m^3$} = 1.25\ \mathrm{g/L} \times 1\ \mathrm{kg}/1000\ \mathrm{g} \times 1000\ \mathrm{L}/1\ \mathrm{m^3$} = 1.25\ \mathrm{kg/m^3$}$$

Q: A student needs to convert $$60.0\ \mathrm{miles/hour} to$$ $$\mathrm{meters/second}. $$Which of the following is the correct setup for this conversion?

$$60.0\ \mathrm{miles/hour} \times \frac{1.609\ \mathrm{km}}{1\ \mathrm{mile}} \times \frac{1000\ \mathrm{m}}{1\ \mathrm{km}} \times \frac{1\ \mathrm{hour}}{3600\ \mathrm{s}}$$

Question 1

Which of the following statements best distinguishes 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. According to the Law of Constant Composition, which of the following samples must also be the same compound?

Accepted Answer

A sample containing 24.0 g of carbon and 64.0 g of oxygen.

Question 3

Which of the following is an example of an intensive property?

Accepted Answer

Density

Question 4

A student measures the mass of a metal sample as 8.50 g and its volume as 3.40 mL. What is the density of the metal in $$\mathrm{g/mL}$$, and how many significant figures should the answer have?

Accepted Answer

$$2.50\ \mathrm{g/mL}$$, 3 significant figures

Question 5

Which of the following correctly describes the result of Rutherford’s gold foil experiment?

Accepted Answer

It demonstrated that atoms have a small, dense, positively charged nucleus.

Question 6

Which of the following is the correct formula for the compound formed between magnesium and nitrate ions?

Accepted Answer

$$\mathrm{Mg(NO_3$)_2}$$

Question 7

A certain element has two naturally occurring isotopes: $$^{10}\mathrm{B} ($$atomic mass = $$10.01\ \mathrm{u}$$, abundance = $$19.9\%) $$and $$^{11}\mathrm{B} ($$atomic mass = $$11.01\ \mathrm{u}$$, abundance = $$80.1\%). $$What is the average atomic mass of boron?

Accepted Answer

$$10.81\ \mathrm{u}$$

Question 8

Which of the following correctly names the compound $$\mathrm{$$FeCl_3$$}$$?

Accepted Answer

Iron(III) chloride

Question 9

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

Accepted Answer

$$298.2\ \mathrm{K}$$

Question 10

Which of the following is a correct statement about ions?

Accepted Answer

Cations have fewer electrons than protons.

Question 11

Which of the following is the empirical formula for a compound with the molecular formula $$\mathrm{C_6H_{12}O_6$}$$?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 12

A sample of gas has a density of $$1.25\ \mathrm{g/L} at$$ $$25.0\ ^\circ\mathrm{C}. $$What is the density in $$\mathrm{kg/m^3$}$$?

Accepted Answer

$$1.25\ \mathrm{kg/L} 	imes 1000\ \mathrm{L/m^3$} = 1.25\ \mathrm{g/L} 	imes 1\ \mathrm{kg}/1000\ \mathrm{g} 	imes 1000\ \mathrm{L}/1\ \mathrm{m^3$} = 1.25\ \mathrm{kg/m^3$}$$

Question 13

Which of the following is a diatomic element in its natural state?

Accepted Answer

Nitrogen

Question 14

Which of the following is the correct name for $$\mathrm{H_2SO_4}$$?

Accepted Answer

Sulfuric acid

Question 15

A student needs to convert $$60.0\ \mathrm{miles/hour} to$$ $$\mathrm{meters/second}. $$Which of the following is the correct setup for this conversion?

Accepted Answer

$$60.0\ \mathrm{miles/hour} 	imes \frac{1.609\ \mathrm{km}}{1\ \mathrm{mile}} 	imes \frac{1000\ \mathrm{m}}{1\ \mathrm{km}} 	imes \frac{1\ \mathrm{hour}}{3600\ \mathrm{s}}$$

Question 16

Which of the following best describes the difference between accuracy and precision?

Accepted Answer

Accuracy is the closeness to the true value; precision is the reproducibility of measurements.

Question 17

Which of the following is the correct name for $$\mathrm{N_2O_5}$$?

Accepted Answer

Dinitrogen pentoxide

Question 18

Which of the following is a correct statement about the periodic table?

Accepted Answer

Transition metals are located in the center of the table, between Groups 2A and 3A.

Question 19

A neutral atom of chlorine has an atomic number of 17 and a mass number of 35. How many protons, neutrons, and electrons does it have?

Accepted Answer

17 protons, 18 neutrons, 17 electrons

Question 20

Which of the following is the correct name for $$\mathrm{K_2SO_4}$$?

Accepted Answer

Potassium sulfate

General Chemistry Exam 1 Review: Matter, Measurement, Atoms, Molecules, and Ions

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