Balancing Chemical Equations
Balance the following chemical equation:
H₂ + O₂ → H₂O
2H₂ + O₂ → 2H₂O
How many moles are in 24 grams of carbon? (Atomic mass of carbon = 12 g/mol)
24 grams / 12 g/mol = 2 moles
How many grams of H₂O are produced from 2 moles of H₂? (Molar mass of H₂O = 18 g/mol)
2 moles × 18 g/mol = 36 grams
In the reaction 2H₂ + O₂ → 2H₂O, if you have 5 moles of H₂ and 3 moles of O₂, which is the limiting reactant?
H₂ is the limiting reactant.
What is the molar mass of H₂SO₄? (H = 1 g/mol, S = 32 g/mol, O = 16 g/mol)
2(1 g/mol) + 32 g/mol + 4(16 g/mol) = 98 g/mol
Balance the following chemical equation:
N₂ + H₂ → NH₃
N₂ + 3H₂ → 2NH₃
How many grams are in 0.5 moles of H₂O? (Molar mass of H₂O = 18 g/mol)
0.5 moles × 18 g/mol = 9 grams
How many moles of CO₂ are produced from 88 grams of CO₂? (Molar mass of CO₂ = 44 g/mol)
88 grams / 44 g/mol = 2 moles
In the reaction N₂ + 3H₂ → 2NH₃, if you have 1 mole of N₂ and 4 moles of H₂, how many moles of NH₃ can be produced?
1 mole N₂ × (2 moles NH₃ / 1 mole N₂) = 2 moles NH₃
Calculate the molar mass of Na₂CO₃. (Na = 23 g/mol, C = 12 g/mol, O = 16 g/mol)
2(23 g/mol) + 12 g/mol + 3(16 g/mol) = 106 g/mol
Balance the following chemical equation:
C₂H₆ + O₂ → CO₂ + H₂O
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
What is the molar mass of CO₂? (C = 12 g/mol, O = 16 g/mol)
12 g/mol + 2 × 16 g/mol = 44 g/mol
How many grams of NaOH are in 0.25 moles? (Molar mass of NaOH = 40 g/mol)
0.25 moles × 40 g/mol = 10 grams
In the reaction 4Fe + 3O₂ → 2Fe₂O₃, if you have 8 moles of Fe and 5 moles of O₂, which is the limiting reactant?
O₂ is the limiting reactant.
Determine the molar mass of Ca(OH)₂. (Ca = 40 g/mol, O = 16 g/mol, H = 1 g/mol)
40 g/mol + 2(16 g/mol) + 2(1 g/mol) = 74 g/mol
Balance the following chemical equation:
Fe + O₂ → Fe₂O₃
4Fe + 3O₂ → 2Fe₂O₃
How many moles are in 58.5 grams of NaCl? (Molar mass of NaCl = 58.5 g/mol)
58.5 grams / 58.5 g/mol = 1 mole
How many moles of H₂O are in 36 grams of H₂O? (Molar mass of H₂O = 18 g/mol)
36 grams / 18 g/mol = 2 moles
In the reaction 2Al + 3Cl₂ → 2AlCl₃, if you have 2 moles of Al and 2 moles of Cl₂, which is the limiting reactant?
Cl₂ is the limiting reactant.
What is the molar mass of C₆H₁₂O₆? (C = 12 g/mol, H = 1 g/mol, O = 16 g/mol)
6(12 g/mol) + 12(1 g/mol) + 6(16 g/mol) = 180 g/mol
Balance the following chemical equation:
KClO₃ → KCl + O₂
2KClO₃ → 2KCl + 3O₂
How many molecules are in 1 mole of any substance? (Avogadro's number)
6.022 × 10²³ molecules
How many grams of CO₂ are produced from 3 moles? (Molar mass of CO₂ = 44 g/mol)
3 moles × 44 g/mol = 132 grams
In the reaction C₂H₆ + O₂ → CO₂ + H₂O, if you have 3 moles of C₂H₆ and 10 moles of O₂, which is the limiting reactant?
O₂ is the limiting reactant.
Find the molar mass of MgCl₂. (Mg = 24 g/mol, Cl = 35.5 g/mol)
24 g/mol + 2(35.5 g/mol) = 95 g/mol