Question

The hydrated salt Na2SO4.nH2O, undergoes 55% loss in weight on heating and becomes anhydrous. The value of n will be

Answer 1

Answer:Na2SO4 molecular mass =142 gm

45 % of weight of Na2SO4 =142 gm

55% of weight of water ?

55x142/45 =173.5 gm

Moles of H2O 173.5/18 =9.65 =n

Explanation:

If you take 55.9% of water loses than you get n=10 mole

Answer 2

The value of n will be 10.

Explanation:

$Na_2SO_4.nH_2O\rightarrow Na_2SO_4+nH_2O$

Molar mass of $Na_2SO_4$ = 142 g/mol

According to stoichiometry:

(142+18) g of $Na_2SO_4.nH_2O$ decomposes to give 18n g of $H_2O$

Thus 100 g of  $Na_2SO_4.nH_2O$ decomposes to give =$\frac{18n}{142+18n}\times 100g$ of $Na_2SO_4$

As given :

$\frac{18}{142+18n}\times 100g=55$

$n=10$  

Thus the value of n is 10.

Learn more about hydrated salts

https://brainly.com/question/4355575

#learnwithbrainly