Question 1

Which of the following best describes the difference between a molecule of an element and a molecule of a compound?

Accepted Answer

A molecule of an element contains two or more atoms of the same element joined together, while a molecule of a compound contains two or more atoms of different elements joined together.

Question 2

A student measures the mass of a sample three times and obtains values that are very close to each other, but far from the true value. Which of the following best describes the measurements?

Accepted Answer

The measurements are precise but not accurate.

Question 3

Which of the following numbers has exactly four significant figures?

Accepted Answer

$$7.0010$$

Question 4

A 25.0 mL sample of sterilizing alcohol contains 15.0 g of isopropanol. What is the density of the mixture in $$\mathrm{g/mL}$$?

Accepted Answer

$$0.600\ \mathrm{g/mL}$$

Question 5

Which of the following statements about isotopes is correct?

Accepted Answer

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

Question 6

Chlorine has two stable isotopes: $$^{35}\mathrm{Cl} ($$mass = $$34.97$$ amu, abundance = $$75.53\%) $$and $$^{37}\mathrm{Cl} ($$mass = $$36.97$$ amu, abundance = $$24.47\%). $$What is the average atomic mass of chlorine?

Accepted Answer

$$35.45$$ amu

Question 7

How many moles of $$\mathrm{Pb}$$ atoms are present in $$0.105\ \mathrm{cm}^3 of $$lead? (Density of lead = $$11.34\ \mathrm{g/cm}^3$$, molar mass = $$207.2\ \mathrm{g/mol})$$

Accepted Answer

$$0.00575$$ mol

Question 8

Which of the following best describes the difference between an ionic compound and a molecular compound?

Accepted Answer

Ionic compounds are formed from metals and non-metals, while molecular compounds are formed from non-metals only.

Question 9

A sample of isobutyl propionate ($$\mathrm{C}_x\mathrm{H}_y\mathrm{O}_z) $$weighing $$1.152\ \mathrm{g} is $$combusted, producing $$2.726\ \mathrm{g} of$$ $$\mathrm{CO}_2$$ and $$1.116\ \mathrm{g} of$$ $$\mathrm{H}_2\mathrm{O}. $$What is the empirical formula of isobutyl propionate?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_2$$

Question 10

Which of the following is the correct net ionic equation for the reaction between aqueous solutions of $$\mathrm{AgNO}_3$$ and $$\mathrm{NaCl}$$?

Accepted Answer

$$\mathrm{Ag}^+(aq) + \mathrm{Cl}^-(aq) \rightarrow \mathrm{AgCl}(s)$$

Question 11

Which of the following is a strong electrolyte in aqueous solution?

Accepted Answer

$$\mathrm{NaCl}$$

Question 12

A $$15.00\ \mathrm{mL}$$ sample of $$0.450\ \mathrm{M}\ \mathrm{K}_2\mathrm{CrO}_4 is $$diluted to $$100.00\ \mathrm{mL}. $$What is the new concentration?

Accepted Answer

$$0.0675\ \mathrm{M}$$

Question 13

Which of the following is the correct balanced equation for the reaction of aluminum hydroxide with sulfuric acid?

Accepted Answer

$$3\mathrm{H}_2\mathrm{SO}_4 + 2\mathrm{Al(OH)}_3 \rightarrow \mathrm{Al}_2(\mathrm{SO}_4)_3 + 6\mathrm{H}_2\mathrm{O}$$

Question 14

A reaction yields $$45.0\ \mathrm{g} of $$cyclohexene ($$\mathrm{C}_6\mathrm{H}_{10}) $$from cyclohexanol ($$\mathrm{C}_6\mathrm{H}_{11}\mathrm{OH}) $$with a verified yield of $$86.2\%. If $$the starting cyclohexanol is $$92.3\%$$ pure, what mass of starting material is required?

Accepted Answer

$$63.2\ \mathrm{g}$$

Question 15

Which of the following is the correct net ionic equation for the neutralization of hydrochloric acid with sodium hydroxide?

Accepted Answer

$$\mathrm{H}^+(aq) + \mathrm{OH}^-(aq) \rightarrow \mathrm{H}_2\mathrm{O}(l)$$

Question 16

A solution contains $$0.438\ \mathrm{M}\ \mathrm{NaCl}$$ and $$0.0512\ \mathrm{M}\ \mathrm{MgCl}_2. $$What is the total chloride ion concentration?

Accepted Answer

$$0.540\ \mathrm{M}$$

Question 17

In a titration, $$15.2\ \mathrm{mL} of$$ $$0.100\ \mathrm{M}\ \mathrm{NaOH} is $$required to reach the equivalence point with $$10.0\ \mathrm{mL} of$$ $$\mathrm{HNO}_3. $$What is the initial concentration of the acid?

Accepted Answer

$$0.152\ \mathrm{M}$$

Question 18

Which of the following is a weak base?

Accepted Answer

$$\mathrm{NH}_3$$

General Chemistry I: Matter, Atoms, Compounds, and Reactions – Study Notes

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