Chapter 9

Challenge Write the word equation and the skeleton equation for the following reaction: when heated, solid potassium chloride yields solid potassium chloride and oxygen gas.

Explain why it is important that a chemical equation be balanced.

List three types of physical evidence that indicate a chemical reaction has occurred.

Compare and contrast a skeleton equation and a chemical equation.

Analyze When balancing a chemical equation, can you adjust the subscript in a formula? Explain.

Assess Is the following equation balanced? If not, correct the coefficients to balance the equation. $$2 \mathrm{K}_{2} \mathrm{CrO}_{4}(\mathrm{aq})+\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}(\mathrm{aq}) \rightarrow 2 \mathrm{KNO}_{3}(\mathrm{aq})+\mathrm{PbCrO}_{4}(\mathrm{s})$$

Evaluate Aqueous phosphoric acid and aqueous calcium hydroxide react to form solid calcium phosphate and water. Write a balanced chemical equation for this reaction.

The solids aluminum and sulfur react to produce aluminum sulfide.

$$\mathrm{K}(\mathrm{s})+\mathrm{ZnCl}_{2}(\mathrm{aq}) \rightarrow$$

Aqueous sodium oxalate and aqueous lead(ll) nitrate react to produce solid lead(ll) oxalate and aqueous sodium nitrate.

Describe the four types of chemical reactions and their characteristics.

Explain how an activity series of metals is organized.

Compare and contrast single-replacement reactions and double-replacement reactions.

Classify What type of reaction is most likely to occur when barium reacts with fluorine? Write the chemical equation for the reaction.

Aqueous solutions of ammonium phosphate and sodium sulfate are mixed. No precipitate forms and no gas is produced.

List three common types of products produced by reactions that occur in aqueous solutions.

Describe solvents and solutes in an aqueous solution.

Distinguish between a complete ionic equation and a net ionic equation.

Write complete ionic and net ionic equations for the reaction between sulfuric acid \(\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)\) and calcium carbonate \(\left(\mathrm{Ca} \mathrm{CO}_{3}\right) .\) $$\mathrm{H}_{2} \mathrm{SO}_{4}(\mathrm{aq})+\mathrm{CaCO}_{3}(\mathrm{s}) \rightarrow \mathrm{H}_{2} \mathrm{O}(\mathrm{l})+\mathrm{CO}_{2}(\mathrm{g})+\mathrm{CaSO}_{4}(\mathrm{aq})$$

Predict What type of product would the following reaction be most likely to produce? Explain your reasoning. $$\mathrm{Ba}(\mathrm{OH})_{2}(\mathrm{aq})+2 \mathrm{HCl}(\mathrm{aq}) \rightarrow$$

Formulate Equations A reaction occurs when nitric acid (HNO \(_{3} )\) is mixed with an aqueous solution of potassium hydrogen carbonate. Aqueous potassium nitrate is produced. Write the chemical and net ionic equations for the reaction.

Define chemical equation.

Distinguish between a chemical reaction and a chemical equation.

Explain the difference between reactants and products.

Does a conversion of a substance into a new substance always indicate that a chemical reaction has occurred? Explain.

Write formulas for the following substances and designate their physical states. $$\begin{array}{l}{\text { a. nitrogen dioxide gas }} \\ {\text { b. liquid gallium }} \\ {\text { c. barium chloride dissolved in water }} \\ {\text { d. solid ammonium carbonate }}\end{array}$$

Identify the reactants in the following reaction: When potassium is dropped into aqueous zinc nitrate, zinc and aqueous potassium nitrate form.

Balance the reaction of hydrogen sulfide with atmospheric oxygen gas. $$\mathrm{H}_{2} \mathrm{S}(\mathrm{g})+\mathrm{O}_{2}(\mathrm{g}) \rightarrow \mathrm{SO}_{2}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g})$$

Write word equations for the following skeleton equations. $$\begin{array}{l}{\text { a. } \mathrm{Cu}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{g}) \rightarrow \mathrm{CuO}(\mathrm{s})} \\ {\text { b. } \mathrm{K}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{KOH}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{g})} \\ {\text { c. } \mathrm{CaCl}_{2}(\mathrm{aq})+\mathrm{Na}_{2} \mathrm{SO}_{4}(\mathrm{aq}) \rightarrow \mathrm{CaSO}_{4}(\mathrm{s})+\mathrm{NaCl}(\mathrm{aq})}\end{array}$$

Balance the following reactions. $$\begin{array}{l}{\text { a. }\left(\mathrm{NH}_{4}\right)_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}(\mathrm{s}) \rightarrow \mathrm{Cr}_{2} \mathrm{O}_{3}(\mathrm{s})+\mathrm{N}_{2}(\mathrm{g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g})} \\ {\text { b. } \mathrm{CO}_{2}(\mathrm{g})+\mathrm{H}_{2} \mathrm{O}(1) \rightarrow \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{g})}\end{array}$$

Hydrogen iodide gas breaks down into hydrogen gas and iodine gas during a decomposition reaction. Write a skeleton equation for this reaction.

Write skeleton equations for these reactions. $$\begin{array}{c}{\text { a. sodium carbonate(s) } \rightarrow} \\ {\text { sodium oxide(s) }+\text { carbon dioxide }(g)}\end{array}$$ $$\begin{array}{l}{\text { b. aluminum(s) }+\text { iodine(s) } \rightarrow \text { aluminum iodide(s) }} \\ {\text { c. iron(II) oxide(s) }+\text { oxygen(g) } \rightarrow \text { iron(III) oxide(s) }}\end{array}$$

Write skeleton equations for these reactions. $$\begin{array}{c}{\text { a. butane }\left(\mathrm{C}_{4} \mathrm{H}_{10}\right)(1)+\text { oxygen }(\mathrm{g}) \rightarrow} \\ {\text { carbon dioxide }(\mathrm{g})+\text { water }(1)}\end{array}$$ $$\begin{array}{c}{\text { b. aluminum carbonate(s) } \rightarrow} \\ {\text { aluminum oxide }(s)+\text { carbon dioxide }(g)}\end{array}$$ $$\begin{array}{c}{\text { c. silver nitrate }(a q)+\text { sodium sulfide }(a q) \rightarrow} \\ {\text { silver sulfide }(s)+\text { sodium nitrate }(a q)}\end{array}$$

Write a skeleton equation for the reaction between lithium(s) and chlorine gas to produce lithium chloride(s).

Write skeleton equations for these reactions. $$a.\operatorname{iron}(\mathrm{s})+\text { fluorine(g) } \rightarrow$$ $$b. sulfur trioxide(g)+\text { water }(1) \rightarrow \text { sulfuric acid }(a q)$$ $$\begin{array}{c}{\text { c. sodium (s) + magnesium iodide }(a q) \rightarrow} \\ {\text { sodium iodide }(a q)+\text { magnesium (s) }}\end{array}$$ $$d. vanadium (s)+\text { oxygen }(g) \rightarrow \text { vanadium }(V) \text { oxide }(s)$$

Write skeleton equations for these reactions. $$a.lithium+\text { gold (III) chloride }(a q) \rightarrow lithium chloride (a q)+gold(s)$$ $$\begin{array}{c}{\text { b. iron(s) }+\operatorname{tin}(\mathrm{IV}) \text { nitrate }(\mathrm{aq}) \rightarrow} \\ {\text { iron (\textrm{III} ) } \text { nitrate }(\mathrm{aq})+\operatorname{tin}(\mathrm{s})}\end{array}$$ $$\begin{array}{c}{\text { c. nickel(II) chloride(s) + oxygen (g) } \rightarrow} \\ {\text { nickel(II) oxide(s) + dichlorine pentoxide(g) }}\end{array}$$ $$\begin{array}{c}{\text { d. lithium chromate(aq) + barium chloride (aq) } \rightarrow} \\ {\text { lithium chloride(aq) }+\text { barium chromate(s) }}\end{array}$$

Write chemical equations for these reactions. a. When solid naphthalene \(\left(\mathrm{C}_{10} \mathrm{H}_{8}\right)\) burns in air, the reaction yields gaseous carbon dioxide and liquid water. b. Bubbling hydrogen sulfide gas through manganese(II) chloride dissolved in water results in the formation of the precipitate manganese(II) sulfide and hydrochloric acid. c. Solid magnesium reacts with nitrogen gas to produce solid magnesium nitride. d. Heating oxygen difluoride gas yields oxygen gas and fluorine gas.

List each of the four types of chemical reactions and give an example for each type.

How would you classify a chemical reaction between two reactants that produces one product?

Write a balanced chemical equation for the combustion of liquid methanol \(\left(\mathrm{CH}_{3} \mathrm{OH}\right)\)

Write chemical equations for each of the following synthesis reactions. $$\begin{array}{l}{\text { a. boron }+\text { fluorine } \rightarrow} \\\ {\text { b. germanium }+\text { sulfur } \rightarrow} \\ {\text { c. zirconium }+\text { nitrogen } \rightarrow} \\ {\text { d. tetraphosphorus decoxide + water } \rightarrow \text { phosphoric acid }}\end{array}$$

Combustion Write a chemical equation for the combustion of each of the following substances. If a compound contains carbon and hydrogen, assume that carbon dioxide gas and liquid water are produced. $$\begin{array}{l}{\text { a. solid barium }} \\ {\text { b. solid boron }} \\\ {\text { c. liquid acetone }\left(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}\right)} \\ {\text { d. liquid octane }\left(\mathrm{C}_{8} \mathrm{H}_{18}\right)}\end{array}$$

Write chemical equations for each of the following decomposition reactions. One or more products might be identified. $$\begin{array}{l}{\text { a. magnesium bromide } \rightarrow} \\ {\text { b. cobalt(II) oxide } \rightarrow} \\ {\text { c. titanium(IV) hydroxide } titanium (IV) oxide + water \rightarrow} \\ {\text { d. barium carbonate } \rightarrow \text { barium oxide }+\text { carbon dioxide }}\end{array}$$

Write chemical equations for the following single-replacement reactions that might occur in water. If no reaction occurs, write \(N R\) in place of the products. $$\begin{array}{l}{\text { a. nickel + magnesium chloride } \rightarrow} \\\ {\text { b. calcium + copper(II) bromide } \rightarrow} \\ {\text { c. potassium + aluminum nitrate } \rightarrow} \\ {\text { d. magnesium }+\text { silver nitrate } \rightarrow}\end{array}$$

Define each of the following terms: solution, solvent, and solute.

When reactions occur in aqueous solutions, what common types of products are produced?

Compare and contrast chemical equations and ionic equations.

What is a net ionic equation? How does it differ from a complete ionic equation?

Define spectator ion.

Write the net ionic equation for a chemical reaction that occurs in an aqueous solution and produces water.