Question 1

Which of the following statements best distinguishes between a physical and a chemical property?

Accepted Answer

A physical property can be observed without changing the substance's identity, while a chemical property can only be observed by changing the substance into a different substance.

Question 2

A student measures the mass of a metal cylinder as $$12.30\ \mathrm{g}$$ and its volume as $$4.1\ \mathrm{cm}^3. $$What is the density of the cylinder, reported with the correct number of significant figures?

Accepted Answer

$$3.0\ \mathrm{g/cm}^3$$

Question 3

Which of the following is an example of a heterogeneous mixture?

Accepted Answer

Sand and iron filings

Question 4

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

Accepted Answer

$$298.15\ \mathrm{K}$$

Question 5

Which scientist is credited with discovering the electron?

Accepted Answer

J. J. Thomson

Question 6

A neutral atom of $$^{37}\mathrm{Cl}$$ has:

Accepted Answer

17 protons, 20 neutrons, 17 electrons

Question 7

Which of the following compounds is ionic?

Accepted Answer

$$\mathrm{NaCl}$$

Question 8

What is the correct name for $$\mathrm{Fe}_2\mathrm{O}_3$$?

Accepted Answer

Iron(III) oxide

Question 9

Calculate the average atomic mass of magnesium if $$^{24}\mathrm{Mg} (78.99$$%, mass = 23.985 amu), $$^{25}\mathrm{Mg} (10.00$$%, mass = 24.986 amu), and $$^{26}\mathrm{Mg} (11.01$$%, mass = 25.983 amu) are present.

Accepted Answer

$$24.31\ \mathrm{amu}$$

Question 10

Which of the following is the correct formula for ammonium sulfate?

Accepted Answer

$$\mathrm{(NH}_4)_2\mathrm{SO}_4$$

Question 11

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen by mass. What is its empirical formula?

Accepted Answer

$$\mathrm{CH}_2\mathrm{O}$$

Question 12

Balance the following equation: $$\mathrm{C}_3\mathrm{H}_8 + \mathrm{O}_2 \rightarrow \mathrm{CO}_2 + \mathrm{H}_2\mathrm{O}$$

Accepted Answer

$$\mathrm{C}_3\mathrm{H}_8 + 5\ \mathrm{O}_2 \rightarrow 3\ \mathrm{CO}_2 + 4\ \mathrm{H}_2\mathrm{O}$$

Question 13

How many moles of $$\mathrm{CO}_2$$ are produced when $$44.0\ \mathrm{g} of$$ $$\mathrm{C}_2\mathrm{H}_6 ($$ethane, molar mass $$30.0\ \mathrm{g/mol}) is $$completely combusted? (Balanced equation: $$2\ \mathrm{C}_2\mathrm{H}_6 + 7\ \mathrm{O}_2 \rightarrow 4\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O})$$

Accepted Answer

$$2.93\ \mathrm{mol}$$

Question 14

A reaction has a theoretical yield of $$10.0\ \mathrm{g}$$ but only $$7.5\ \mathrm{g} of $$product is actually obtained. What is the percent yield?

Accepted Answer

$$75\%$$

Question 15

Which of the following is an extensive property?

Accepted Answer

Mass

Question 16

How many significant figures are in the measurement $$0.004560\ \mathrm{g}$$?

Accepted Answer

4

Question 17

Which of the following is the correct name for $$\mathrm{N}_2\mathrm{O}_5$$?

Accepted Answer

Dinitrogen pentoxide

Question 18

A sample contains $$3.01 	imes 10$$^{23}$$ molecules of $$\mathrm{H}_2\mathrm{O}$$. How many moles of water are present?

Accepted Answer

$$0.500\ \mathrm{mol}$$

Question 19

Which of the following best describes the role of the limiting reactant in a chemical reaction?

Accepted Answer

It determines the amount of product formed.

Question 20

A solution is prepared by dissolving $$5.00\ \mathrm{g} of $$NaCl (molar mass $$58.44\ \mathrm{g/mol}) in $$enough water to make $$250.0\ \mathrm{mL} of $$solution. What is the molarity of the solution?

Accepted Answer

$$0.342\ \mathrm{M}$$

General Chemistry Exam 1 Study Guide: Matter, Atomic Structure, and Stoichiometry

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