Question

what is the mass percent of water in cobalt(ii) chloride hexahydrate? provide an answer to two decimal places.

Explanation:

Step1: Find molar mass of \( CoCl_2 \cdot 6H_2O \)

Molar mass of \( Co \): \( 58.93 \, g/mol \), \( Cl \): \( 35.45 \, g/mol \), \( H_2O \): \( 18.02 \, g/mol \).
Molar mass of \( CoCl_2 \): \( 58.93 + 2\times35.45 = 129.83 \, g/mol \).
Molar mass of \( 6H_2O \): \( 6\times18.02 = 108.12 \, g/mol \).
Total molar mass: \( 129.83 + 108.12 = 237.95 \, g/mol \).

Step2: Calculate mass percent of water

Mass percent formula: \( \frac{\text{Mass of water}}{\text{Total mass}} \times 100 \).
\( \frac{108.12}{237.95} \times 100 \approx 45.44\% \).

Answer:

\( 45.44\% \)