Balancing Chemical Equations

A

100

Because matter is conserved in a chemical change, add coefficients to balance this equation for mass.

__ Al(C₂H₃O₂)₃ + __ K₂CO₃ → __ Al₂(CO₃)₃ + __ KC₂H₃O₂

2 Al(C₂H₃O₂)₃ + 3 K₂CO₃ → 1 Al₂(CO₃)₃ + 6 KC₂H₃O₂

200

Write the BCE for the synthesis of ammonia, NH₃, from its elements

N₂ + 3H₂ → 2NH₃

300

Write the balanced chemical equation for the reaction between aqueous solutions of ammonium hydroxide and aluminum chloride.

3NH₄OH + AlCl₃ → 3NH₄Cl + Al(OH)₃

400

Write a balanced chemical equation for the reaction that occurs when calcium is dropped into water.

Ca + 2HOH → Ca(OH)₂ + H₂

500

Write the net ionic equation for the ppt formed when aqueous solutions of sodium sulfate and silver nitrate react.

SO₄^-2 + 2Ag⁺¹ → Ag₂SO₄

B

100

Write the chemical formulas for potassium phosphate

K₃PO₄

200

Water can be decomposed into its elements using electrolysis. Write a balanced chemical equation for the electrolysis of water.

2H₂O → 2H₂ + O₂

300

Write the chemical formulas only for the compounds below that are soluble in water.

lead (II) chromate
ammonium carbonate
lithium oxide
silver iodide
calcium sulfide
cupric nitrate

(NH₄)₂CO₃
Li₂O
CaS
Cu(NO₃)₂

400

For the reaction below that occurs, write a balanced chemical equation.

Zn + AlCl₃ →
Al + ZnCl₂ →

2Al + 3ZnCl₂ → 2AlCl₃ + 3Zn

500

Ionic compounds that are soluble in water dissociate into ions. An overall ionic equation shows this separation of soluble compounds into ions. Write the overall ionic equation for the following reaction

2FeCl₃ + 3Na₂CO₃ → Fe₂(CO₃)₃ + 6NaCl

2Fe⁺³ + 6Cl^-1 + 6Na⁺¹ + 3CO₃^-2 → Fe₂(CO₃)₃↓ + 6Na⁺¹ + 6Cl^-1

C

100

Write a balanced chemical equation for the synthesis reaction shown below.


The ferrous sulfide that is formed where the yolk and the white meet can turn the yolk a greenish color if an egg is boiled too long.

Hydrogen peroxide produces water and hydrogen gas when it is heated.

Fe + S → FeS

200

What should you observe that would suggest to you that a chemical change occurs when you place a piece of sodium into water?

Fizzing. The hydrogen gas that is produced when sodium reacts with water fizzes. 2Na + 2HOH → 2NaOH + H₂

300

Not all metals react with acid. For each reaction below that DOES occur, write a balanced chemical equation.

Cu + HCl →
Mg + HCl →
Al + HCl →

Mg + 2HCl → MgCl₂ + H₂

2Al + 6HCl → 2AlCl₃ + 3H₂

400

Identify the spectator ions in the following overall ionic equation.

Ca⁺² + 2NO₃^-1 + 2Na⁺¹ + CO₃^-2 → CaCO₃↓ + 2Na⁺¹ + 2NO₃^-1

Na⁺¹ and NO₃^-1

500

Which halogen is most active?

bromine
chlorine
fluorine
iodine

Explain your logic.

Fluorine. It is higher than the other halogens on the activity series, therefore, it can replace the halogens below it, making it the most active halogen.