Balancing Chemical Equations 1. Solid calcium metal reacts with water to form aqueous calcium hydroxide and hydrogen gas. Ca(s) + 2H2O(ℓ) → Ca(OH)2(aq) + H2 (g) 2. Nitrogen dioxide gas reacts with water to form aqueous hydrogen nitrate (nitric acid) and nitrogen monoxide gas. 3NO2(g)+ H2O(ℓ) → 2HNO3(aq) + NO(g) 3. Solid potassium chlorate decomposes to form solid potassium chlorate and oxygen gas. 2KClO3 → 2KCl(s) + 3O2(g) 4. Solid zinc oxide is made by reacting solid zinc sulfide with oxygen gas. Sulfur dioxide gas is also produced. 2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g) 5. Solid calcium phosphate is reacted with aqueous sulfuric acid (hydrogen sulfate) to form phosphoric acid (hydrogen phosphate) and solid calcium sulfate. Ca3(PO4)2 (s) + 3H2SO4(aq) → 2H3PO4(aq) + 3CaSO4(s) 6. Solid sodium combines with chlorine gas to produce solid sodium chloride. 2Na(s) + Cl2(g) → 2NaCl(s) 7. When solid copper reacts with aqueous silver nitrate the products are aqueous copper(II) nitrate and solid silver. Cu(s) + 2AgNO3 → Cu(NO3)2(aq) + 2Ag(s) 8. In a blast furnace, the reaction between solid iron(III) oxide and carbon monoxide gas produces solid iron and carbon dioxide gas. Fe2O3(s) +3CO(g)
2Fe(s) + 3CO2(g)
9. When solid lithium reacts with aqueous aluminum sulfate the products are aqueous lithium sulfate and solid aluminum. 6Li(s) + Al2(SO4)3(aq) → 3Li2SO4(aq) + 2Al(s) 10. Hydrogen sulfide gas and oxygen gas produce sulfur dioxide gas and water vapor. 2H2S(g) + 3O2(g) → 2SO2(g) + 2H2O(g)