The number of grams of oxygen in 0.10 mol of Na2CO3 . 10H2O is ……(

1.	The number of grams of oxygen in 0.10 mol of Na2CO3 . 10H2O is ……(a) 20.8 g (b) 18 g (c) 108 g (d) 13 g
Answer» (a) 20.8 g Na₂CO₂ .10H₂O = 1 mole 1 mole of Na₂CO₃ . 10H₂O contains 13 oxygen atoms. Mass of 13 oxygen atoms = 13 x 16 = 208 1 mole of Na₂CO₃ .10H₂O contains 208 g of oxygen. ∴ 0.10 mole of Na₂CO₃.10H₂O contains 208/1 x 0.12 = 08 g.

The number of grams of oxygen in 0.10 mol of Na2CO3 . 10H2O is ……(a) 20.8 g (b) 18 g (c) 108 g (d) 13 g

Answer»

(a) 20.8 g

Na₂CO₂ .10H₂O = 1 mole

1 mole of Na₂CO₃ . 10H₂O contains 13 oxygen atoms.

Mass of 13 oxygen atoms = 13 x 16 = 208

1 mole of Na₂CO₃ .10H₂O contains 208 g of oxygen.

∴ 0.10 mole of Na₂CO₃.10H₂O contains 208/1 x 0.12 = 08 g.