A reaction starts with 20.0 grams of lithium hydroxide (LiOH) and produces 31.0 grams of lithium chloride (LiCl), what is the percent yield of lithium chloride (LiCl)

64.5%

88.6%

81.5%

92.8%

The answer is 87.5%

Explanation:

Step 1:

The balanced equation for the reaction. This is given below:

LiOH + HCl - > LiCl + H2O

Step 2:

Determination of the mass of LiOH that reacted and the mass of LiCl produced from the balanced equation. This is illustrated below:

Molar mass of LiOH = 6.9 + 16 + 1.01 = 23.91g/mol

Mass of LiOH from the balanced equation = 1 x 23.91 = 23.91g

Molar Mass of mass of LiCl = 6.9 + 35.45 = 42.35g/mol

Mass of LiCl from the balanced equation = 1 x 42.35 = 42.35g

Summary:

From the balanced equation above,

23.91g of LiOH reacted to produce 42.35g of LiCl.

Step 3:

Determination of the theoretical yield of LiCl.

The theoretical yield of LiCl can be obtained as follow:

From the balanced equation above,

23.91g of LiOH reacted to produce 42.35g of LiCl.

Therefore, 20g of LiOH will react to produce = (20 x 42.35) / 23.91 = 35.42g of LiCl.

Therefore, the theoretical yield of LiCl is 35.42g

Step 4:

Determination of the percentage yield of LiCl.

Actual yield of LiCl = 31g

Theoretical yield of LiCl = 35.42g

Percentage yield = ?

Percentage yield = Actual yield / Theoretical yield x100

Percentage yield = 31/35.42 x 100

Percentage yield = 87.5%