Problem 28
When a chemical drain opener is added to a clogged sink, bubbles form and the water in the sink gets warmer. Has a chemical reaction occurred? Explain your answer.
Problem 32
For each chemical equation (which may or may not be balanced), list the number of each type of atom on each side of the equation, and determine if the equation is balanced. (a) \(\mathrm{MgS}(a q)+2 \mathrm{CuCl}_{2}(a q) \longrightarrow 2 \mathrm{CuS}(s)+\mathrm{MgCl}_{2}(a q)\) (b) \(2 \mathrm{C}_{6} \mathrm{H}_{14}(l)+19 \mathrm{O}_{2}(g) \longrightarrow 12 \mathrm{CO}_{2}(g)+14 \mathrm{H}_{2} \mathrm{O}(g)\)
Problem 33
Consider the unbalanced chemical equation. $$ \mathrm{H}_{2} \mathrm{O}(l) \underset{\text { electrical current }}{\longrightarrow} \mathrm{H}_{2}(g)+\mathrm{O}_{2}(g) $$ A chemistry student tries to balance the equation by placing the subscript 2 after the oxygen atom in \(\mathrm{H}_{2} \mathrm{O}\). Explain why this is not correct. What is the correct balanced equation?
Problem 34
Consider the unbalanced chemical equation. $$ \mathrm{Al}(s)+\mathrm{Cl}_{2}(g) \longrightarrow \mathrm{AlCl}_{3}(s) $$ A student tries to balance the equation by changing the subscript 2 on \(\mathrm{Cl}\) to a 3 . Explain why this is not correct. What is the correct balanced equation?
Problem 35
Write a balanced chemical equation for each chemical reaction. (a) Solid lead(II) sulfide reacts with aqueous hydrochloric acid to form solid lead(II) chloride and dihydrogen sulfide gas. (b) Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane \(\left(\mathrm{CH}_{4}\right)\) and liquid water. (c) Solid iron(III) oxide reacts with hydrogen gas to form solid iron and liquid water. (d) Gaseous ammonia \(\left(\mathrm{NH}_{3}\right)\) reacts with gaseous oxygen to form gaseous nitrogen monoxide and gaseous water.
Problem 36
Write a balanced chemical equation for each chemical reaction. (a) Solid copper reacts with solid sulfur to form solid copper(I) sulfide. (b) Sulfur dioxide gas reacts with oxygen gas to form sulfur trioxide gas. (c) Aqueous hydrochloric acid reacts with solid manganese(IV) oxide to form aqueous manganese(II) chloride, liquid water, and chlorine gas. (d) Liquid benzene \(\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)\) reacts with gaseous oxygen to form carbon dioxide and liquid water.
Problem 37
Write a balanced chemical equation for each chemical reaction. (a) Solid magnesium reacts with aqueous copper(I) nitrate to form aqueous magnesium nitrate and solid copper. (b) Gaseous dinitrogen pentoxide decomposes to form nitrogen dioxide and oxygen gas. (c) Solid calcium reacts with aqueous nitric acid to form aqueous calcium nitrate and hydrogen gas. (d) Liquid methanol \(\left(\mathrm{CH}_{3} \mathrm{OH}\right)\) reacts with oxygen gas to form gaseous carbon dioxide and gaseous water.
Problem 38
Write a balanced chemical equation for each chemical reaction. (a) Gaseous acetylene \(\left(\mathrm{C}_{2} \mathrm{H}_{2}\right)\) reacts with oxygen gas to form gaseous carbon dioxide and gaseous water. (b) Chlorine gas reacts with aqueous potassium iodide to form solid iodine and aqueous potassium chloride. (c) Solid lithium oxide reacts with liquid water to form aqueous lithium hydroxide. (d) Gaseous carbon monoxide reacts with oxygen gas to form carbon dioxide gas.
Problem 39
When solid sodium is added to liquid water, it reacts with the water to produce hydrogen gas and aqueous sodium hydroxide. Write a balanced chemical equation for this reaction.
Problem 40
When iron rusts, solid iron reacts with gaseous oxygen to form solid iron(III) oxide. Write a balanced chemical equation for this reaction.
