Question

A 10.11 g sample of NaBr contains 22.34 % Na by mass. Considering the law of constant composition (definite proportions), how many grams of sodium does a 7.09 g sample of sodium bromide contain

Answer 1

Answer:

$1.58\ \text{g}$

Explanation:

10.11 g sample of $NaBr$ contains 22.34% $Na$ by mass

According to the law of constant composition the if one sample of $NaBr$ has 22.34% of $Na$ by mass then any other sample of $NaBr$ will have the same percentage of the amount of $Na$.

For a sample of 7.09 g we have

$7.09\times \dfrac{22.34}{100}=1.583906\approx 1.58\ \text{g}$

The mass of sodium in the required sample is $1.58\ \text{g}$.