Question

The number of molecules of water in 333 g of Al2(SO4)3.18H2O is (A) 18x6.02x1023 (B) 9x6.02x1023 (C) 18 (D) 36​
please tell step by step explanation
I am In 7th std
please

Answer 1

Answer:

b

Step-by-step explanation:

given Al2(SO4)3.18H2O

Molar mass = 2 X 27 + 3 X(32+64) + 18 X 18

                   =         666 gm

So number of Moles = weight/molar mass

                                 =  333/6666

                                 = 0.5 moles

So 1 mole of Al2(SO4).18H2O contains 18 moles of water

So 0.5 mols of Al2(SO4).18H2O conatins 9 moles of water.

so answer is 9 moles of water.