Answer:
percentage yield = 88.25%
Explanation:
Firstly, write the chemical reaction and balance the equation.
Potassium react with oxygen to produce potassium oxide.
K + 02 → K2O
Balance the equation
4K + 02 → 2K2O
The limiting reactant is K so the yield of potassium oxide can be calculated using grams for potassium.
atomic mass of K = 39.1g/mol
grams for 4 mole of potassium = 4(39.1) = 156.4 g
grams for 2 moles of K2O = 2( 39.1 × 2 + 16) = 188.4 g
If 156.4 g of K produces 188.4 g of K2O
6.92 g of K will produce ? gram of K2O
cross multiply
grams of K2O = 6.92 × 188.4/156.4
grams of K2O = 1303.72/156.4
grams of K2O = 8.33585677749
grams of K2O = 8.34 g
percentage yield = actual yield/theoretical yield × 100
actual yield = 7.36 g
theoretical yield = 8.34 g
percentage yield = 7.36/8.34 × 100
percentage yield = 736/8.34
percentage yield = 88.2494004796%
percentage yield = 88.25%
