Question

4g of calcium metal is burned in oxygen of air to form calcium oxide. (Ca = 40, O= 16, at STP: 32g of oxygen has 22.4L)

Find the mass of the calcium oxide

Find the volume of the required air if the volume of oxygen is 1/5 time of the volume of air.?
pls help need it right now!!

Answer 1

m=4 g Ca

M=ArCa+ArO=56 g/mol

Ca+O2-2CaO

nCa= m/M= 4/40=0.1 moles of Ca

the ratio of moles: 1 mole Ca:2 moles CaO

0.1 moles Ca =0.2 moles CaO

n=m/M

m=n×M

m=0.2×56=11.2 g CaO