Balancing Equations
Balance:
__H2+__O2 → __H2O
2H2+O2 → 2H2O
What type of reaction is this?
2KClO3 → 2KCl+3O2
Decomposition
Find the limiting reactant:
2H₂ + O₂ → 2H₂O
There are 4 moles of H₂ and 1 mole of O₂
O₂
Calculate the molar mass of Na₂CO₃
105.99 g/mol
A sample has a mass of 25.0 g and a volume of 5.00 mL. What is its density?
5 g/mL
Balance:
__KClO3 → __KCl+__O2
2KClO3 → 2KCl+3O2
What type of reaction is this?
Zn + 2HCl → ZnCl₂ + H₂
Single Displacement
Find the limiting reactant:
N₂ + 3H₂ → 2NH₃
There are 2 moles of N₂ and 3 moles of H₂
H₂
How many moles are in 25.0 g of Na₂CO₃?
0.236 mol
A solution contains 0.500 mol of solute in 2.00 L of solution. Calculate the molarity.
0.250 M
Balance:
Ca(OH)2+H2SO4 → CaSO4+2H2O
Ca(OH)2+H2SO4 → CaSO4+2H2O
It's already balanced!
What type of reaction is this?
AgNO₃ + NaCl → AgCl + NaNO₃
Double Displacement
Identify the limiting reactant and calculate the moles of H₂O produced:
2H₂ + O₂ → 2H₂O
There are 4 moles of H₂ and 1 mole of O₂
O₂ is the limiting reactant and there are 2 moles of H₂O
What mass is equal to 0.500 mol Na₂CO₃?
53.0 g
You have a 2.00 M stock solution and need to prepare 100.0 mL of 0.500 M solution. What volume of the stock solution is needed?
25 mL
Balance:
__Al+__O2 → __Al2O3
4Al+3O2 → 2Al2O3
You have a mixture of sand and water. What separation technique would be most appropriate?
Filtration
Identify the limiting reactant and calculate the theoretical mass of H₂O:
2H₂ + O₂ → 2H₂O
There are 4 moles of H₂ and 1 mole of O₂
O₂ is the limiting reactant and the theoretical mass of H₂O is 36 g
If 10.0 g CaCO₃ decomposes, how many grams of CO₂ can be produced?
CaCO₃ → CaO + CO₂
4.40 g CO₂
A reaction has a theoretical yield of 15.0 g. The experiment produces 12.0 g. Calculate the percent yield.
80%
Balance:
__Al(OH)3 → __Al2O3+__H2O
2Al(OH)3 → Al2O3+3H2O
Match each situation with the best separation technique:
A. Separate an insoluble solid from a liquid
B. Separate a liquid from a settled solid by pouring
C. Separate substances with different boiling points
D. Transfer a substance between solvents based on solubility
E. Separate a solid that changes directly into a gas
A → Filtration
B → Decantation
C → Distillation
D → Extraction
E → Sublimation
Identify the limiting reactant and calculate the theoretical yield of AlCl₃ in grams:
2Al + 3Cl₂ → 2AlCl₃
A reaction contains 10 g Al and 20 g Cl₂
Cl₂ is the limiting reactant and there's a theoretical yield of 25.1 g of AlCl₃
A student is solving CaCO₃ → CaO + CO₂ for the mass of CO2 produced
They write:
10.0 g CaCO₃ × 1 mol CaCO₃ / 100.09 g CaCO₃ = 0.0999 mol
Then they write:
0.0999 g CO₂
They stopped too early. They didn't convert
mol CaCO₃ → mol CO₂ → g CO₂
A sample has a mass of 12.50 g, and volume of 5.2 mL. Calculate the density and report your answer using the correct number of significant figures.
2.4 g/mL