Relay Answer Key HAS
1. Envelope 1
1) Zinc pellets are placed in a solution of copper (II) nitrate to make solid copper and a solution of zinc (II) nitrate.
Write a balanced equation. What type of reaction is this?
i. Cu(NO3)2 + Zn  Cu + Zn(NO3)2
ii. SD
2) Hexane (C6H14) is burned. Write the balanced equation. What type of reaction is this?
i. 2 C6H14 + 19 O2  12 CO2 + 14 H2O
ii. Combustion
3) Write the following reaction using the correct terms. What type of reaction is this?
2 Al(s) + 3 Pb(NO3)2(aq)  3 Pb(s) + 2 Al(NO3)3(aq)
i. Aluminum metal is added to lead (II) nitrate solution and produces solid lead and aluminum nitrate solution.
ii. SD
4) Magnesium hydroxide reacts with hydrogen chloride, a double-displacement reaction occurs and produces
magnesium chloride and water. If you start with 525.0mg of Magnesium hydroxide, how many atoms do you have?
i. Mg(OH)2 + 2HCl  MgCl2 + 2H2O
1.00 g
1 mole
6.022x1023 f.u.
5 atoms
1000 mg
58.33 g
Mg(OH)2
1 mole
1 f.u.
525.0 mg
Mg(OH)2
= 2.71x1022
atoms
5) 42 kilograms of Copper (II) Phosphate reacts with 9.11x10 25 formula units of Potassium hydroxide in a double
displacement reaction to produce copper (II) hydroxide and potassium phosphate. How many kilograms of
Potassium hydroxide have been made?
i. Cu3(PO4)2 + KOH  Cu(OH)2 + K3PO4
9.11x10 25 fu
KOH
2.
1 mole
56.11 g KOH
1 kg
6.022x1023 f.u.
1 mole
1000 g
= 8.49 kg KOH
Envelope 2
1) Write the following reaction using the correct terms. What type of reaction is this? 2 KClO3  2 KCl + 3 O2
i. Potassium chlorate is broken down into potassium chloride and oxygen gas.
ii. Decomposition
2) Solid aluminum metal is placed in a solution of lead (II) nitrate to make solid lead and aluminum nitrate. Write a
balanced equation. What type of reaction is this?
i. 2 Al(s) + 3 Pb(NO3)2(aq)  3 Pb(s) + 2 Al(NO3)3(aq)
ii. Double displacement
3) Benzene (C6H6) is burned. Write the balanced equation. What type of reaction is this?
i. 2C6H6 + 15O2  12CO2 + 6H2O
ii. Combustion
4) 42 kilograms of Copper (II) Phosphate reacts with 9.11x10 25 formula units of Potassium hydroxide in a double
displacement reaction to produce copper (II) hydroxide and potassium phosphate. How many formula units of
Copper (II) Phosphate have been made?
42 kg Cu3(PO4)2
1000 g
1 mole
6.022x1023 f.u.
1 kg
380.59 g Cu3(PO4)2
1 mole
= 6.64 x1022 f.u.
5) A solution of aluminum sulfate and a solution of calcium hydroxide will react in a double displacement reaction to
produce calcium sulfate and aluminum hydroxide. How many grams of aluminum sulfate are there containing
9.275x1039 atoms?
9.275x1039 atoms
Al2(SO4)3
3.
1 f.u. Al2(SO4)3
1 mole
342.17 g
17 atoms
6.022x1023 f.u.
1 mole
= 3.100x1017grams of
Al2(SO4)3
Envelope 3
1) Write the following reaction using the correct terms. What type of reaction is this?
2 Al(s) + 3 Pb(NO3)2(aq)  3 Pb(s) + 2 Al(NO3)3(aq)
i. Aluminum solid is added to lead nitrate solution and yields lead solid and aluminum nitrate solution
ii. Single displacement
2) Heptane (C7H14) is burned. Write the balanced equation. What type of reaction is this?
i. 2 C7H14 + 21O2  14CO2 + 14H2O
ii. Combustion
3) Solid lead (II) sulfate and liquid water are formed from an aqueous solution of hydrogen peroxide (dihydrogen
dioxide) and solid lead (II) sulfide. Write a balanced equation. What type of reaction is this?
i. PbSO4 + 4H2O  4H2O2 + PbS
ii. Double displacement
4) Heating solid copper (I) oxide will cause a decomposition reaction that produces oxygen gas and copper metal. If
2.408x1025 molecules of copper (I) oxide were made, how many grams of copper (I) oxide was there to begin with?
2.408x1025 molecules
Cu2O
1 mol Cu2O
143.1 g
6.022x1023 mlc
Cu2O
1 mole Cu2O
= 5722 grams Cu2O
5) Potassium hydroxide reacts with copper (II) phosphate in a double displacement reaction that produces copper (II)
hydroxide and potassium phosphate. If you start with 0.72 kilograms of copper (II) phosphate, how many formula
units are there?
0.72 kg Cu3(PO4)2
1000 g
1 mole
6.022x1023 f.u.
= 1.37 x1021f.u
1 kg
4.
317.04 grams
1 mole
Envelope 4
1) Solid aluminum metal is placed in a solution of lead (II) nitrate to make solid lead and aluminum nitrate. Write a
balanced equation. What type of reaction is this?
i. 2 Al(s) + 3 Pb(NO3)2(aq)  3 Pb(s) + 2 Al(NO3)3(aq)
ii. Double displacement
2) Write the following reaction using the correct terms. What type of reaction is this?
2 KClO3  2 KCl + 3 O2
i. Potassium chlorate is broken down into potassium chloride and oxygen gas.
ii. Decomposition
3) Pentane (C5H12) is burned. Write the balanced equation. What type of reaction is this?
i. 2C5H12 + 15O2  12CO2 + 6H2O
ii. Combustion
4) Calcium iodide solution is poured into a solution of mercury (IV) nitrate resulting in a double displacement reaction
that produces calcium nitrate and mercury (IV) iodide. If 22 kilograms of mercury (IV) nitrate are used, how many
formula units are there?
22 kg Hg(NO3)4
1000 g
1 mole
6.022x1023 f.u.
1 kg
448.63 g
1 mole
= 3.0 x1025 f.u. of
Hg(NO3)4
5) A solution of aluminum sulfate and a solution of calcium hydroxide will react in a double displacement reaction to
produce calcium sulfate and aluminum hydroxide. How many grams of aluminum sulfate are there containing
1.533x1035 atoms?
1.533x1035 atoms
Al2(SO4)3
1 f.u. Al2(SO4)3
1 mole
342.17 g
17 atoms
6.022x1023 f.u.
1 mole
= 5.124 x 1012 grams
of Al2(SO4)3