Stoichiometry Examples

Mass to Mass Calculations

Balanced Equation3 A + 2 B = 3 C + 1 D Given x g of A, find amount of mass (#) of B required for the reaction

x g A x 1 mol A = y mol A molar mass g A

y mol A x 2 mol B = z mol B(from the balanced equation) 3 mol A

z mol B x molar mass g B = # g B 1 mol B

2 A + 1 B = 1 C + 2 D Calculate mass (#) of A to yield x g of C,

x g C x 1 mol C = y mol C molar mass g C

y mol C x 2 mol A = z mol A(from the balanced equation) 1 mol C

z mol A x molar mass g A = # g A 1 mol A

Mass to Volume Calculations

Balanced Equation2 A + 6 B = 2 C + 3 D Given x g of A, find volume of gas (L) of D produced

x g A x 1 mol A = y mol A molar mass g A

y mol A x 3 mol D = z mol D(from the balanced equation) 2 mol A

z mol D x 22.4 L D = # L D 1 mol D

2 A = 2 B + 3 C Calculate volume (L) of gas of C given x g of A

x g A x 1 mol A = y mol A molar mass g A

y mol A x 3 mol C = z mol C(from the balanced equation) 2 mol A

z mol C x 22.4 L C = # L C 1 mol C

Volume to Volume Calculations

Balanced Equation2 A + 1 B = 2 C Given x L of A, find volume of gas (L) of B that reacts to produce C

x L A x 1 L B = y L B(from the balanced equation) 2 L A

Now calculate the L of C

y L A x 2 L C = z L C 2 L A

1 A + 3 B = 2 C Given x L of A, find volume of gas (L) of C that is produced

x L A x 2 L C = y L C(from the balanced equation) 1 L A

Percent Yield Calculations

Actual Yield x 100%= percent yieldTheoretical Yield