Question

When 10.0g of calcium metal is reacted with water, 5.00g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield of the reaction.

Ca(s) + 2 H₂O(l) → Ca(OH)₂(aq) + H₂(g)


A) 92.4%
B) 27.1%
C) 50.0%
D) 13.5%

Answer 1

The percent yield of the reaction can be calculated by dividing the actual yield by the theoretical yield and multiplying by 100.

Step-by-step explanation:

The percent yield of a reaction is calculated by dividing the actual yield by the theoretical yield, and then multiplying by 100. In this case, the actual yield is given as 5.00g of calcium hydroxide. To find the theoretical yield, we need to calculate the molar mass of calcium hydroxide. Ca(OH)2 consists of one calcium atom (40.08 g/mol) and two hydroxide ions (2(16.00 g/mol + 1.01 g/mol)). Adding these masses gives a molar mass of 74.09 g/mol for calcium hydroxide. Therefore, the theoretical yield can be calculated by dividing the mass of calcium hydroxide by its molar mass and multiplying by 100.

The calculation is as follows:

Theoretical yield = (mass of calcium hydroxide / molar mass of calcium hydroxide) x 100

Theoretical yield = (5.00g / 74.09 g/mol) x 100

= 6.75%

Finally, to calculate the percent yield, divide the actual yield by the theoretical yield and multiply by 100:

Percent yield = (actual yield / theoretical yield) x 100

Percent yield = (5.00g / 6.75%) x 100

Percent yield = 74.1%