# Ch.7-Writing and balancing chemical equations and precipitation reaction equations

During photosynthesis plants use carbon dioxide and water to make glucose and release oxygen. The equation for this reaction is:
6 CO? + 6 H?O ? C?H??O? + 6 O?
When methane (CH?) is burned on a stove in produces carbon dioxide and water. The equation for this reaction is:
CH?(g) + 2 O?(g) ? CO?(g) + 2 H?O(g)
The reaction between solid silicon dioxide and solid carbon produces solid silicon carbide and carbon monoxide gas. The equation for this reaction is:
SiO?(s) + 3 C(s) ? SiC(s) + 2 CO(g)
The combustion of liquid octane (C?H??) produces gaseous carbon dioxide and water. The equation for this reaction is:
2 C?H??(l) + 25 O?(g) ? 16 CO?(g) + 18 H?O
The reaction between solid chromium(III) oxide and solid carbon produced solid chromium and carbon dioxide gas. The equation for this reaction is:
2 Cr?O?(s) + 3 C(s) ? 4 Cr(s) + 3 CO?(g)
Solid aluminum reacts with aqueous sulfuric acid to form aqueous aluminum sulfate and hydrogen gas. The equation for this reaction is:
2 Al(s) + 3 H?SO? ? Al?(SO?)? + 3 H?
Solid iron reacts with aqueous hydrochloric acid to form aqueous iron(III) chloride and hydrogen gas. The equation for this reaction is:
2 Fe(s) + 6 HCl(aq) ? 2 FeCl?(aq) + 3 H?(g)
Balance this chemical equation:
HCl(g) + O?(g) ? H?O(l) + Cl?
4 HCl(g) + O? ? 2 H?O + 2 Cl?
Write an equation for when sodium carbonate ad copper(II) chloride are mixed. Does a precipitation reaction occur?
Na?CO?(aq) + CuCl?(aq) ? 2 NaCl(aq) + CuCO?(s)
Write an equation for the reaction that occurs when lead(II) acetate and sodium sulfate are mixed. Does a precipitation reaction occur?
Pb(C?H?O?)?(aq) + Na?SO?(aq) ? PbSO?(s) + 2 Na(C?H?O?)(aq)
Write an equation for the reaction that occurs when potassium hydroxide and nickel(II) bromide solutions are mixed. Does a precipitation reaction occur?
2 KOH(aq)+NiBr?(aq) ? Ni(OH)?(s)+2 KBr(aq)
Write an equation for the reaction that occurs when solutions of ammonium chloride and iron(III) nitrate are mixed. Does a precipitation reaction occur?
3 NH?Cl(aq) + Fe(NO?)?(aq) ? 3 NH?NO?(aq) + FeCl?(aq)
Write an equation for the reaction that occurs when solutions of potassium sulfate and strontium nitrate are mixed. Does a precipitation reaction occur?
K?SO?(aq) + Sr(NO?)?(aq) ? 2 KNO?(aq) + SrSO?(s)
Balance the following:
Cr(s) + S?(s) ? Cr?S?
16 Cr(s) + 3 S?(s) ? 8 Cr?S?
Balance the following:
Fe?S?(s)+ HCl(g) ? FeCl?(s) + H?S(g)
Fe?S?(s)+ 6 HCl(g) ? 2 FeCl?(s) + 3 H?S(g)
Balance the following:
Na(s) + H?O(l) ? NaOH(aq) + H?(g)
2 Na(s) + 2 H?O(l) ? 2 NaOH(aq) + H?(g)
Balance the following and determine if there is a precipitation reaction occur when:
CuNO?(aq) + KOH(aq) ?
CuNO?(aq)+ KOH(aq) ? CuOH(s)+ KNO?(aq)
Balance the following and determine if there is a precipitation reaction occur when:
Na?S(aq) + CaCl?(aq) ?
Na?S(aq) + CaCl?(aq) ? 2 NaCl(aq) + CaS(s)
Balance the following and determine if there is a precipitation reaction occur when:
Al(NO?)?(aq) + KOH(aq) ?
Al(NO?)? + 3KOH ? Al(OH)?(s) + 3KNO?(aq)
Balance the following:
H?O(l) ? H?(g) + O?(g)
2 H?O(l) ? 2 H?(g) + O?(g)
Write a balanced equation for: Solid lead(II) sulfide reacts with aqueous hydrochloric acid to form solid lead(II) chloride and dihydrogen sulfide gas
PbS(s) + 2 HCl(aq) ? PbCl?(s) + H?S(g)
Balance:
CO + H? ? CH? + H?O
CO + 3 H? ? CH? + H?O
Balance:
Fe?O? + H? ? Fe + H?O
Fe?O? + 3 H? ? 2 Fe + 3 H?O
Write a balanced equation for: Gaseous ammonia reacts with gaseous oxygen to form gaseous nitrogen monoxide and gaseous water
4 NH?(g) + 5 O?(g) ? 4 NO(g) + 6 H?O(g)
Write a balanced equation for:
Solid magnesium reacts with aqueous copper(I) nitrate to form aqueous magnesium nitrate and solid copper.
Mg(s) + 2 CuNO?(aq) ? Mg(NO?)?(aq) + 2 Cu(s)
Write a balanced equation for:
Gaseous dinitrogen pentoxide decomposes to form nitrogen dioxide and oxygen gas.
2 N?O?(g) ? 4 NO?(g) + O?(g)
Balance:
Ca + HNO? ? Ca(NO?)? + H?
Ca + 2 HNO? ? Ca(NO?)? + H?
Balance:
CH?OH + O? ? CO? + H?O
2 CH?OH + 3 O? ? 2 CO? + 4 H?O
Balance:
Na?S + Cu(NO?)? ? NaNO? + CuS
Na?S + Cu(NO?)? ? 2 NaNO? + CuS
Balance:
HCl + O? ? H?O + Cl?
4 HCl + O? ? 2 H?O + 2 Cl?
Balance:
FeS + HCl ? FeCl? + H?S
FeS + 2 HCl ? FeCl? + H?S
Balance the following and determine if there is a precipitation reaction occur when:
Na?CO? + Pb(NO?)??
Na?CO?(aq) + Pb(NO?)?(aq) ? PbCO?(s) + 2 NaNO?(aq)
Balance:
B?O? + HF ? BF? + H?O
B?O? + 6 HF ? 2 BF? + 3 H?O
Balance:
PH? + O? ? P?O?? + H?O
4 PH? + 8 O? ? P?O?? + 6 H?O
Write a balanced equation for: Aluminum metal reacts with iron(II) sulfide to form aluminum sulfide and iron metal.
2 Al + 3 FeS ? Al?S? + 3 Fe
Write a balanced equation for:
Calcium phosphate reacts with sulfuric acid to form calcium sulfate and phosphoric acid.
Ca?(PO?)? + 3 H?SO? ? 3 CaSO? + 2 H?PO?
Balance the following and determine if there is a precipitation reaction occur when:
K?SO? + Pb(NO?)? ?
K?SO?(aq) + Pb(NO?)?(aq) ? PbSO?(s) + 2 KNO?(aq)