Question

40 g of calcium was extracted from 56 g of calcium oxide
(Atomic mass of Ca= 40, O=16)
i) What mass of oxygen 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 1

first = mass of oxygen is 16 grams