Nitrous oxide $($N$2$O$)$ having a mass of $3\mathrm{.}89$ g reacts completely with an equimolar amount of NO$2$ to form elemental nitrogen and oxygen. What is the mass of N$2$ formed in this reaction?

Enter the value with the appropriate number of significant figures. $$

g

$2.$ The fuel tank of an automobile contains $69\mathrm{.}0$ kg of gasoline. If the gasoline reacts completely with excess oxygen $($from the air$)$ to form CO$2$ and H$2$O$,$ what is the total mass of the products? For simplicity, assume that gasoline is comprised of $100\%$ octane.$($C$8$H$18).$

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kg

$3.$ What is the mass percent composition of oxygen in a compound having the empirical formula C$16$H$30$O$2?$

Include at least $3$ significant figures in your answer. $$

percent

$4.$ What is the total mass of oxygen in $5\mathrm{.}47$ g of iron$($III$)$ oxide?

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g

$5.$ Acid rain is caused in part by burning coal that contains sulfur impurities. The sulfur is converted first to SO$2,$ which reacts with oxygen and atmospheric moisture to produce sulfuric acid, H$2$SO$4.$ If a particular coal contains $2\mathrm{.}55\%$ sulfur $($by mass$),$ calculate the mass of sulfuric acid produced by burning a metric ton $(1000$ kg$)$ of the coal.

Enter the value with the appropriate number of significant figures. $$

kg