Q: A student needs to convert $$5.00\ \mathrm{cm^3$} to $$liters. Which of the following is the correct conversion?

$$5.00 \times 10$$^{-3}$$\ \mathrm{L}$$

Q: A student is asked to convert $$2.50\ \mathrm{km^2$} to$$ $$\mathrm{m^2$}. $$Which of the following is the correct answer?

$$2.50 \times 10$$^{6}$$\ \mathrm{m^2$}$$

Question 1

Which of the following statements best describes the difference between precision and accuracy in scientific measurements?

Accepted Answer

Precision refers to how close repeated measurements are to each other, while accuracy refers to how close a measurement is to the true value.

Question 2

A student measures the mass of a sample as 0.04560 g. Which of the following statements about the significant figures in this measurement is correct?

Accepted Answer

The zeros after the decimal point and after the 6 are significant, but the leading zero is not.

Question 3

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

Accepted Answer

Mass

Question 4

A sample of ethanol has a mass of 46.0 g and a volume of 58.0 mL. What is the density of ethanol in $$\mathrm{g/cm^3$}$$? (Note: $$1\ \mathrm{mL} = 1\ \mathrm{cm^3$})$$

Accepted Answer

$$0.793\ \mathrm{g/cm^3$}$$

Question 5

Which of the following best describes the Law of Definite Proportions?

Accepted Answer

A given compound always contains the same elements in the same proportion by mass.

Question 6

Which of the following is an example of a chemical change?

Accepted Answer

Iron rusting in moist air

Question 7

A student needs to convert $$5.00\ \mathrm{cm^3$} to $$liters. Which of the following is the correct conversion?

Accepted Answer

$$5.00 	imes 10$$^{-3}$$\ \mathrm{L}$$

Question 8

Which of the following is NOT a postulate of Dalton’s Atomic Theory?

Accepted Answer

Atoms are composed of protons, neutrons, and electrons.

Question 9

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons.

Question 10

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

Accepted Answer

$$0.500$$ mol

Question 11

Which of the following is the correct way to express the chemical symbol for an atom of carbon-14?

Accepted Answer

$$^{14}_{6}\mathrm{C}$$

Question 12

Which of the following is an example of an exact number?

Accepted Answer

There are 12 eggs in a dozen.

Question 13

Which of the following best describes the process of sublimation?

Accepted Answer

A solid changing directly to a gas, requiring an increase in energy.

Question 14

Which of the following statements about the arrangement of the periodic table is correct?

Accepted Answer

Elements are arranged in order of increasing atomic number.

Question 15

A compound is found to contain 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is the empirical formula of the compound?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 16

Which of the following is a correct statement about the Law of Conservation of Energy?

Accepted Answer

Energy cannot be created or destroyed, only transformed from one form to another.

Question 17

A student is asked to convert $$2.50\ \mathrm{km^2$} to$$ $$\mathrm{m^2$}. $$Which of the following is the correct answer?

Accepted Answer

$$2.50 	imes 10$$^{6}$$\ \mathrm{m^2$}$$

Question 18

Which of the following best describes a heterogeneous mixture?

Accepted Answer

A mixture in which the composition is not uniform throughout.

Question 19

Which of the following is the correct molar mass of $$\mathrm{Na_2SO_4} ($$sodium sulfate)? (Atomic masses: Na = 22.99, S = 32.07, O = 16.00)

Accepted Answer

$$142.05\ \mathrm{g/mol}$$

Question 20

Which of the following best describes dimensional analysis?

Accepted Answer

A method of converting between units using conversion factors to ensure correct units in calculations.

General Chemistry: Measurements, Matter, and Atomic Theory Study Guide

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