Question

What is the percent yield of lithium hydroxide from a reaction of 7.40g of lithium with 10.2g of water? The actual yield was measured to be 12.1g.

Answer 1

Answer:

$\boxed{Percentage \ Yield = 47.6 \ percent}$

Explanation:

The balanced chemical reaction is

$2Li + 2H_{2}O \ \ \ -> \ \ \ 2LiOH + H_{2}$

For the balanced reaction, we've

Lithium = 14 g

Water = 36 g

LiOH = 48 g

Hydrogen gas = 2 g

So,

14 g of lithium = 48 g of lithium hydroxide

And we have:

7.40 g of lithium = x grams of lithium hydroxide

Cross Multiplying,

x grams = $\frac{48*7.4}{14}$

Grams of lithium = 25.4 g of lithium hydroxide

So, Theoretical Yield = 25.4 g of lithium hydroxide

Now, The %age yield:

%age Yield = $\frac{Actual \ Yield}{Theoretical \ Yeild } * 100$

%age Yield = $\frac{12.1}{25.4} * 100$

%age Yield = 47.6%