499 mg sample of CuSO4. xH2O is heated and reweighed to give a mass of 319 mg. Given that the sample contains 2 mmol of Cu; what

Question

3 years ago

11

is the value of x in CuSO4. xH2O.

1 answer:

nevsk [136] · Answer 1 · 2022-05-30T13:30:03+03:00

The value of x in CuSO4. xH2O is 5.

Given that;

Number of moles of anhydrous salt = Number of moles of hydrated salt

Number of moles of anhydrous salt = 319 × $10^-3$

Mass of hydrated salt = 499 × $10^-3$ g

Number of moles of anhydrous salt = 319 $10^-3$ g/160 g/mol = 0.00199 moles

Number of moles of hydrated salt = 499 × $10^-3$ g/ 160 + 18x

0.00199 = 499 × $10^-3$ g/ 160 + 18x

0.00199 (160 + 18x) = 499 × $10^-3$

0.318 + 0.036x = 0.499

0.036x = 0.499 - 0.318

0.036x = 0.181

x = 0.181/0.036

x = 5

Hence, x in CuSO4. xH2O is 5.