Question

In CuSO4.5H2O the percentage of water is ......
(Cu = 63.5, S = 32, 0 = 16, H= 1)
a. 10 % b. 36 %
c. 60 % d. 72 %​

Answer 1

Answer:

Option b is correct

Use percentage composition

Answer 2

Answer: The correct answer is Option b.

Explanation:

We are given:

Atomic mass of copper = 63.5 u

Atomic mass of sulfur = 32 u

Atomic mass of oxygen = 16 u

Atomic mass of hydrogen = 1 u

To calculate the percentage of water in $CuSO_4.5H_2O$, we use the equation:

$\text{Mass percent of water}=\frac{\text{Mass of water}}{\text{Mass of }CuSO_4.5H_2O}\times 100$

Mass of $CuSO_4.5H_2O=[63.5+32+(4\times 16)+5((2\times 1)+16)]=249.5u$

Mass of $5H_2O=5\times [(2\times 1)+16)]=90u$

Putting values in above equation, we get:

$\text{Mass percent of water}=\frac{90u}{249.5u}\times 100\\\\\text{Mass percent of water}=36\%$

Hence, the correct answer is Option b.