Q: How many molecules are present in $$8.14 \times 10$$^{-2}$$ mol of benzene ($$\mathrm{C_6H_6}$$)?

$$\mathrm{5.08 \times 10$$^{22}$$}$$

Q: How many oxygen atoms are present in $$3.76 \times 10$$^{21}$$ molecules of aluminum nitrate ($$\mathrm{Al($$NO_3)_3$$}$$)?

$$\mathrm{3.39 \times 10$$^{22}$$}$$

Question 1

Which of the following is the correctly balanced chemical equation for the complete combustion of octane ($$\mathrm{C_8H_{18}}$$)?

Accepted Answer

$$\mathrm{C_8H_{18}(l) + 12.5\ O_2$(g) \rightarrow 8\ CO_2$(g) + 9\ H_2O(l)}$$

Question 2

Calculate the molar mass of urea ($$\mathrm{CO(NH_2$)_2}).$$

Accepted Answer

$$\mathrm{60.0\ g/mol}$$

Question 3

A sample contains $$100.0\ g of $$urea ($$\mathrm{CO(NH_2$)_2}). $$How many moles of urea are present?

Accepted Answer

$$\mathrm{1.333\ mol}$$

Question 4

What is the percent by mass of nitrogen in urea ($$\mathrm{CO(NH_2$)_2}$$)?

Accepted Answer

$$\mathrm{18.7\%}$$

Question 5

How many molecules are present in $$8.14 	imes 10$$^{-2}$$ mol of benzene ($$\mathrm{C_6H_6}$$)?

Accepted Answer

$$\mathrm{5.08 	imes 10$$^{22}$$}$$

Question 6

How many oxygen atoms are present in $$3.76 	imes 10$$^{21}$$ molecules of aluminum nitrate ($$\mathrm{Al($$NO_3)_3$$}$$)?

Accepted Answer

$$\mathrm{3.39 	imes 10$$^{22}$$}$$

Question 7

Given $$30.0\ g of $$benzene ($$\mathrm{C_6H_6}) $$and $$65.0\ g of $$bromine ($$\mathrm{Br_2$}$$), what is the limiting reagent in the reaction $$\mathrm{C_6H_6 + Br_2$ \rightarrow C_6H_5Br + HBr}$$?

Accepted Answer

Benzene ($$\mathrm{C_6H_6})$$

Question 8

If $$42.3\ g of$$ $$\mathrm{C_6H_5Br} is $$produced from a theoretical yield of $$60.3\ g$$, what is the percent yield?

Accepted Answer

$$\mathrm{70.1\%}$$

Question 9

Which of the following is a strong acid and a strong electrolyte?

Accepted Answer

Hydrobromic acid ($$\mathrm{HBr})$$

Question 10

Which of the following is a weak acid and a weak electrolyte?

Accepted Answer

Acetic acid ($$\mathrm{CH_3COOH})$$

Question 11

What is the net ionic equation for the reaction between $$\mathrm{$$MgSO_4$$(aq)}$$ and $$\mathrm{K_2CO_3(aq)}$$?

Accepted Answer

$$\mathrm{Mg$$^{2+}$$(aq) + CO_3$^{2-}(aq) \rightarrow $$MgCO_3$$(s)}$$

Question 12

What is the net ionic equation for the neutralization of acetic acid ($$\mathrm{CH_3COOH}) $$with barium hydroxide ($$\mathrm{Ba(OH)_2}$$)?

Accepted Answer

$$\mathrm{H^+(aq) + OH^-(aq) \rightarrow H_2O(l)}$$

Question 13

What is the oxidation state of chlorine in $$\mathrm{$$HClO_3$$}$$?

Accepted Answer

$$+3$$

Question 14

In the reaction $$\mathrm{Fe(s) + Cu(NO_3$)_2(aq) \rightarrow Cu(s) + Fe(NO_3$)_2(aq)}$$, which species is oxidized?

Accepted Answer

$$\mathrm{Fe}$$

Question 15

What is the net ionic equation for the reaction between iron and copper(II) nitrate?

Accepted Answer

$$\mathrm{Fe(s) + Cu$$^{2+}$$(aq) \rightarrow Fe$$^{2+}$$(aq) + Cu(s)}$$

Question 16

What is the molarity of a solution prepared by dissolving $$175\ g of $$acetic acid ($$\mathrm{CH_3COOH}$$, molar mass $$60.05\ g/mol) in$$ $$2.00\ L of $$water?

Accepted Answer

$$1.46\ M$$

Question 17

A $$0.30\ M$$ NaCl solution is diluted to three times its original volume. What is the final concentration?

Accepted Answer

$$0.10\ M$$

General Chemistry Study Notes: Stoichiometry, Solutions, Electrolytes, and Chemical Equations

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