Question

data table

1. mass of evaporating dish 50.17 g
2. mass of hydrate 2.49 g
3. mass of evaporating dish and hydrate (before heating) 58.65 g
4. mass of evaporating dish and anhydrous compound (after heating) 57.71 g
5. mass of water in hydrate 0.94 g
6. % water in hydrate

data analysis

Explanation:

Step1: Recall percentage - mass formula

The formula for percentage of water in a hydrate is $\text{Percent water}=\frac{\text{Mass of water}}{\text{Mass of hydrate}}\times100\%$.

Step2: Identify values from data - table

The mass of water in the hydrate is $0.94$ g (from row 5 of the data - table), and the mass of the hydrate is $2.41$ g (from row 2 of the data - table).

Step3: Calculate percentage

Substitute the values into the formula: $\text{Percent water}=\frac{0.94}{2.41}\times 100\%$.
$\frac{0.94}{2.41}\times100\%\approx39.0\%$.

Answer:

$39.0$