The percentage of water of crystallization in ZnSO\(_4\).7H\(_2\)O is?
[Zn = 65, S = 32, O = 16, H = 1]
A
33%
B
44%
C
55%
D
87%
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
molar mass of water [7H\(_2\)O] = 7[ 2 * 1 + 16] → 7 * 18 = 126g/mol
molar mass of ZnSO\(_4\).7H\(_2\)O = [65 * 1] + [32 * 1] + [16 * 4] + 7[ 2 * 1 + 16]
→ 65 + 32 + 64 + 126 = 287g/mol
percentage of water of crystallization = \(\frac{mass of water of crystallization}{mass of hydrated compound} * 100%\)
→ \(\frac{126}{287} * 100\) = 43.9
≈ 44%
Source: WAEC / JAMB / NECO Classroom Archive (Record #4287)