Q: Which of the following is a correct metric conversion using the factor-label method?

$$5.0\ \mathrm{cm} \times \frac{1\ \mathrm{m}}{100\ \mathrm{cm}} = 0.050\ \mathrm{m}$$

Q: What is the percent composition by mass of oxygen in $$\mathrm{H}_2\mathrm{O}$$?

$$\frac{16.00}{18.02} \times 100\% = 88.8\%$$

Q: How many atoms are present in $$2.00\ \mathrm{mol} of $$carbon?

$$2.00 \times 6.02 \times 10$$^{23}$$ = 1.20 \times 10$$^{24}$$ atoms

Q: What is the molar mass of $$\mathrm{Ca(NO_3$)_2}$$?

$$40.08 + 2 \times (14.01 + 3 \times 16.00) = 164.10\ \mathrm{g/mol}$$

Question 1

Which of the following best describes a chemical change?

Accepted Answer

Iron rusting when exposed to air

Question 2

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

Accepted Answer

Density

Question 3

A sample of a compound contains only sodium and chlorine. Which of the following statements is TRUE?

Accepted Answer

It is a pure substance and a compound.

Question 4

Convert 25.0 °C to Kelvin.

Accepted Answer

$$25.0 + 273.15 = 298.15\ \mathrm{K}$$

Question 5

Which of the following is a correct metric conversion using the factor-label method?

Accepted Answer

$$5.0\ \mathrm{cm} 	imes \frac{1\ \mathrm{m}}{100\ \mathrm{cm}} = 0.050\ \mathrm{m}$$

Question 6

A block has a mass of $$250\ \mathrm{g}$$ and a volume of $$50.0\ \mathrm{cm}^3. $$What is its density?

Accepted Answer

$$\frac{250\ \mathrm{g}}{50.0\ \mathrm{cm}^3} = 5.00\ \mathrm{g/cm}^3$$

Question 7

Which of the following is NOT a base SI unit?

Accepted Answer

Liter

Question 8

Which of the following best describes a homogeneous mixture?

Accepted Answer

A glass of salt water

Question 9

Which of the following elements is a metalloid?

Accepted Answer

Silicon

Question 10

Which of the following is the correct name for $$\mathrm{FeCl}_3$$?

Accepted Answer

Iron(III) chloride

Question 11

What is the percent composition by mass of oxygen in $$\mathrm{H}_2\mathrm{O}$$?

Accepted Answer

$$\frac{16.00}{18.02} 	imes 100\% = 88.8\%$$

Question 12

A hydrate of copper(II) sulfate has a mass of $$3.50\ \mathrm{g}$$ before heating and $$2.24\ \mathrm{g}$$ after heating. What is the mass of water lost?

Accepted Answer

$$3.50\ \mathrm{g} - 2.24\ \mathrm{g} = 1.26\ \mathrm{g}$$

Question 13

How many atoms are present in $$2.00\ \mathrm{mol} of $$carbon?

Accepted Answer

$$2.00 	imes 6.02 	imes 10$$^{23}$$ = 1.20 	imes 10$$^{24}$$ atoms

Question 14

What is the molar mass of $$\mathrm{Ca(NO_3$)_2}$$?

Accepted Answer

$$40.08 + 2 	imes (14.01 + 3 	imes 16.00) = 164.10\ \mathrm{g/mol}$$

Question 15

A sample contains $$4.00\ \mathrm{g} of$$ $$\mathrm{He}$$ gas. How many moles of $$\mathrm{He}$$ are present? (Molar mass of $$\mathrm{He} = 4.00\ \mathrm{g/mol})$$

Accepted Answer

$$\frac{4.00\ \mathrm{g}}{4.00\ \mathrm{g/mol}} = 1.00\ \mathrm{mol}$$

Question 16

Which of the following is the correct empirical formula for a compound with $$40.0\%$$ carbon, $$6.7\%$$ hydrogen, and $$53.3\%$$ oxygen by mass?

Accepted Answer

$$\mathrm{CH_2O}$$

Question 17

A $$22.4\ \mathrm{L}$$ sample of a gas at STP contains how many moles?

Accepted Answer

$$1.00\ \mathrm{mol}$$

Question 18

Which of the following is the correct name for $$\mathrm{Na_2SO_4 \cdot 10H_2O}$$?

Accepted Answer

Sodium sulfate decahydrate

Question 19

If $$3.00\ \mathrm{mol} of$$ $$\mathrm{H_2$}$$ react with $$2.00\ \mathrm{mol} of$$ $$\mathrm{O_2$} to $$form water, what is the limiting reactant?

Accepted Answer

$$\mathrm{H_2$}$$

General Chemistry Study Guide: Matter, Measurement, and Chemical Formulas

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