Water and ethanol, $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}(\mathrm{l})$, are miscible, that is, they can be mixed in all proportions. However, when these liquids are mixed, the total volume of the resulting solution is not equal to the sum of the pure liquid volumes, and we say that the volumes are not additive. For example, when $50.0 \mathrm{~mL}$ of water and $50.0 \mathrm{~mL}$ of $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}(1)$, are mixed at $20^{\circ} \mathrm{C}$, the total volume of the solution is $96.5 \mathrm{~mL}$, not $100.0 \mathrm{~mL}$. (The volumes are not additive because the interactions and packing of water molecules are slightly different from the interactions and packing of $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}$ molecules.) Calculate the molarity of $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}$ in a solution prepared by mixing $50.0 \mathrm{~mL}$ of water and $50.0 \mathrm{~mL}$ of $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}(\mathrm{l})$ at $20^{\circ} \mathrm{C}$. At this temperature, the densities of water and ethanol are $0.99821$ $\mathrm{g} / \mathrm{mL}$ and $0.7893 \mathrm{~g} / \mathrm{mL}$, respectively.

The three astronauts aboard Apollo 13, which was launched in 1970 on April 11 and returned to Earth on April 17, were kept alive during their mission, in part, because of lithium hydroxide $(\mathrm{LiOH})$ canisters that were designed to remove exhaled $\mathrm{CO}_2$ from the air. Solid lithium hydroxide reacts with $\mathrm{CO}_2(\mathrm{~g})$ to give solid $\mathrm{Li}_2 \mathrm{CO}_3$ and water. With the assumption that an astronaut exhales approximately $1.00 \mathrm{~kg} \mathrm{CO}_2$ per day, what mass of $\mathrm{LiOH}$ was required to remove all of the $\mathrm{CO}_2$ exhaled by the three-member crew on their six-day mission?

Write a chemical equation to represent the below reaction :
Calcium dihydrogen phosphate reacts with sodium hydrogen carbonate (bicarbonate), producing calcium phosphate, sodium hydrogen phosphate, carbon dioxide, and water (the principal reaction occurring when ordinary baking powder is added to cakes, bread, and biscuits).

Write a chemical equation to represent the below reaction :
White phosphorus and oxygen gas react to form tetraphosphorus decoxide. The tetraphosphorus decoxide reacts with water to form an aqueous solution of phosphoric acid.

Write a chemical equation to represent the below reaction :
Copper metal reacts with gaseous oxygen, carbon dioxide, and water to form green basic copper carbonate, $\mathrm{Cu}_2(\mathrm{OH})_2 \mathrm{CO}_3$ (a reaction responsible for the formation of the green patina, or coating, often seen on outdoor bronze statues).

Write a chemical equation to represent the below reaction :
Calcium phosphate is heated with silicon dioxide and carbon, producing calcium silicate $\left(\mathrm{CaSiO}_3\right)$, phosphorus $\left(\mathrm{P}_4\right)$, and carbon monoxide. The phosphorus and chlorine react to form phosphorus trichloride, and the phosphorus trichloride and water react to form phosphorous acid.

Write a chemical equation to represent the below reaction :
Sulfur dioxide gas is passed into an aqueous solution containing sodium sulfide and sodium carbonate. The reaction products are carbon dioxide and an aqueous solution of sodium thiosulfate.

Write a chemical equation to represent the below reaction :
Propane gas reacts with gaseous water to produce a mixture of carbon monoxide and hydrogen gases. (This mixture, called synthesis gas, is used to produce a variety of organic chemicals.)

Write a chemical equation to represent the below reaction :
Zinc sulfide ore is heated in the air (roasted) and is converted to zinc oxide and sulfur dioxide gas. (Note that oxygen gas in the air is also a reactant.)

Write a chemical equation to represent the below reaction :
Limestone rock (calcium carbonate) is heated (calcined) and decomposes to calcium oxide and carbon dioxide gas.

A mixture of $\mathrm{Fe}_2 \mathrm{O}_3$ and $\mathrm{FeO}$ was analyzed and found to be $72.0 \% \mathrm{Fe}$ by mass. What is the percentage by mass of $\mathrm{Fe}_2 \mathrm{O}_3$ in the mixture?

When a solid mixture of $\mathrm{MgCO}_3$ and $\mathrm{CaCO}_3$ is heated strongly, carbon dioxide gas is given off and a solid mixture of $\mathrm{MgO}$ and $\mathrm{CaO}$ is obtained. If a $24.00 \mathrm{~g}$ sample of a mixture of $\mathrm{MgCO}_3$ and $\mathrm{CaCO}_3$ produces $12.00 \mathrm{~g} \mathrm{CO}_2$, then what is the percentage by mass of $\mathrm{MgCO}_3$ in the original mixture?

The following set of reactions is to be used as the basis of a method for producing nitric acid, $\mathrm{HNO}_3$. Calculate the minimum masses of $\mathrm{N}_2, \mathrm{H}_2$, and $\mathrm{O}_2$ required per kilogram of $\mathrm{HNO}_3$.

$$\begin{aligned} &\mathrm{N}_2(\mathrm{~g})+3 \mathrm{H}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{NH}_3(\mathrm{~g}) \\ &4 \mathrm{NH}_3(\mathrm{~g})+5 \mathrm{O}_2(\mathrm{~g}) \longrightarrow 4 \mathrm{NO}(\mathrm{g})+6 \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \\ &2 \mathrm{NO}(\mathrm{g})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{NO}_2(\mathrm{~g}) \\ &3 \mathrm{NO}_2(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{l}) \longrightarrow 2 \mathrm{HNO}_3(\mathrm{aq})+\mathrm{NO}(\mathrm{g}) \end{aligned}$$

Write balanced equation to represent the complete combustion of glycerol ($\mathrm{CH}_2(\mathrm{OH}) \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_2 \mathrm{OH}(\mathrm{l}))$ following in excess oxygen.