Question

Calculate the number of moles of water in 488 g of bacl2√ó2 H2o

Answer 1

The molar mass (that is the mass of one mole) of BaCl2.2H2O is 244g. Each mole of this compound contains 2 moles of water. Thus

244 g of BaCl2.2H2O → 2 moles of water

1g of BaCl2.2H2O → (2 / 244) moles of water

488 g of BaCl2.2H2O → (2 X 488) / 244 moles of water

= 4 moles of water

So, 488g of BaCl2 contains 4 moles of water.