40g of calcium was extracted from 56 g of calcium oxide (Atomic mass of Ca = 40, O = 16) (i) What mass oxygen is there is there in 56 g of calcium oxide? (ii) How many moles of oxygen atoms are there in this? (iii) How many moles of calcium atoms are there in 40 g of calcium ? (iv) What mass of calcium will be obtained from 1000 g of calcium oxide?

40g of calcium was extracted from 56 g of calcium oxide (Atomic mass

1.	40g of calcium was extracted from 56 g of calcium oxide (Atomic mass of Ca = 40, O = 16) (i) What mass oxygen is there is there in 56 g of calcium oxide? (ii) How many moles of oxygen atoms are there in this? (iii) How many moles of calcium atoms are there in 40 g of calcium ? (iv) What mass of calcium will be obtained from 1000 g of calcium oxide?
Answer» SOLUTION :(i) Mass of `CaO=56g` Mass of `Ca=40g` `therefore"Mass of oxygen "=56-40=16g` (ii) `("No. of moles of oxygen atom")/("Mole = mass/atomic mass")=(16)/(16)=" 1 mole"` 1 mole of oxygen atom (iii) `("No of moles of calcium")/("Mole = mass/atomic mass")=(40)/(40)="1 mole"` 1 mole of calcium atom (IV) 56 g calcium oxide gives 40 g of calcium `therefore"1000 g of calcium oxide given "=(40)/(56)xx1000` `="714.285 g of calcium "= "714.29g of calcium"`