Question 1

A sample of a metal has a mass of 45.0 g and occupies a volume of 16.0 mL. What is the density of the metal in $$\mathrm{g/cm^3$}$$?

Accepted Answer

$$2.81\ \mathrm{g/cm^3$}$$

Question 2

Which of the following best describes a chemical change?

Accepted Answer

Iron rusting in moist air

Question 3

A student measures the mass of a sample three times and obtains values of 2.51 g, 2.50 g, and 2.52 g. The true mass is 2.80 g. Which statement is correct regarding the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 4

Which of the following is a correct statement about isotopes?

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons.

Question 5

A solution is prepared by dissolving 10.0 g of NaCl in 90.0 g of water. Which term best describes this mixture?

Accepted Answer

Homogeneous mixture

Question 6

Which of the following is the correct order of steps in the scientific method?

Accepted Answer

Observation, Hypothesis, Experiment, Theory

Question 7

A sample contains $$3.01 	imes 10$$^{23}$$ atoms of carbon. How many moles of carbon are present?

Accepted Answer

$$0.500\ \mathrm{mol}$$

Question 8

Which of the following is the correct SI unit and prefix for a measurement of $$0.000001$$ meters?

Accepted Answer

1 micrometer ($$1\ \mu\mathrm{m})$$

Question 9

A sample of magnesium has three naturally occurring isotopes: $$^{24}\mathrm{Mg} (78.99$$%, 23.985 amu), $$^{25}\mathrm{Mg} (10.00$$%, 24.986 amu), and $$^{26}\mathrm{Mg} (11.01$$%, 25.983 amu). What is the average atomic mass of magnesium?

Accepted Answer

$$24.31\ \mathrm{amu}$$

Question 10

Which of the following best describes a cation?

Accepted Answer

An atom or molecule that has lost one or more electrons

Question 11

A student adds $$25.0\ ^\circ\mathrm{C}$$ water to a beaker containing $$100.0\ ^\circ\mathrm{C}$$ water. What type of change occurs as the two samples mix and reach a final temperature?

Accepted Answer

Physical change

Question 12

Which of the following is the correct number of significant figures in the result of $$12.01 	imes 0.20$$?

Accepted Answer

2

Question 13

Convert $$98.6\ ^\circ\mathrm{F} ($$normal human body temperature) to Celsius using the formula $$^\circ\mathrm{C} = \frac{5}{9}(^\circ\mathrm{F} - 32). $$What is the result?

Accepted Answer

$$37.0\ ^\circ\mathrm{C}$$

Question 14

Which of the following is a correct definition of a solution?

Accepted Answer

A homogeneous mixture of two or more substances

Question 15

A neutral atom of $$^{35}\mathrm{Cl}$$ has how many protons, neutrons, and electrons?

Accepted Answer

17 protons, 18 neutrons, 17 electrons

Question 16

Which of the following is the correct molar mass of glucose ($$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6$$)? (Atomic masses: C = 12.01, H = 1.008, O = 16.00)

Accepted Answer

$$180.16\ \mathrm{g/mol}$$

Question 17

A sample of a compound contains 40.0 g of carbon and 6.71 g of hydrogen. What is the mass percent of hydrogen in the compound?

Accepted Answer

$$14.4\%$$

Question 18

Which of the following best describes an anion?

Accepted Answer

An atom or molecule that has gained one or more electrons

Question 19

A student mixes sand and iron filings. Which of the following best describes the result?

Accepted Answer

A heterogeneous mixture

Question 20

Which of the following is the correct number of significant figures in the result of $$12.345 + 0.6$$?

Accepted Answer

1

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

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