Question

CaSO4.XH2O looses 6.2% of water upon heating.
The value of x will be
(1) 2
(2) 3
(3) 4
(4)1/2
plz ans it fast
I'll mark it as braniliest ans​

Answer 1

here we can simply use a short trick or formula as :

$\frac{molecular \: wt \: of \: water \: \times x}{mass \: of \: salt \:}$

but he mass of salt to be taken has to be that of before water of crystallisation. here it is CaSO4.

$\frac{18x}{40 + 32 + 64} = 6.2\%$

$\frac{18x}{136} = \frac{6.2}{100}$

here x comes out to be

x=0.46 ~0.5

x=0.5

x=½