Question

In a lab, 33 g of potassium chloride is formed from 60.0 g of potassium chlorate decomposing. Calculate the theoretical yield and percent yield for this experiment.

Answer 1

Answer: The theoretical yield and percent yield for this experiment are 40 g and 82% respectively.

Step-by-step explanation:

`2KClO_3\rightarrow 2KCl+3O_2`

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number
`(6.023* 10^(23))` of particles.

To calculate the moles:

`\text{Moles of potassium chloride}=\frac{\text{Mass of potassium chloride}}{\text{Molar mass of potassium chloride}}=(33g)/(74.5g/mole)=0.44moles`

`\text{Moles of potassium chlorate}=\frac{\text{Mass of potassium chlorate}}{\text{Molar mass of potassium chlorate}}=(66g)/(122.5g/mole)=0.54moles`

According to stochiometry:

2 moles of
`KClO_3` produce = 2 moles of
`KCl`

0.54 moles of
`KClO_3` should produce =
`(2)/(2)* 0.54=0.54moles` of
`KCl`

Thus theoretical yield is
`moles* {\text {Molar mass}}=0.54mol* 74.5g/mol=40g`

But Experimental yield is 33 g.

`{\text {percentage yield}}=\frac{\text {Experimental yield}}{\text {Theoretical yield}}* 100\%`

`{\text {percentage yield}}=(33g)/(40g)* 100\%=82\%`

The theoretical yield and percent yield for this experiment are 40 g and 82% respectively.