What will be the number of (1) moles of ethylene,
(2) molecules of ethylene,
(3) atoms of carbon in 0.28g of ethylene.

Explanation

0.28g of ethylene `=(0.28)/(28)=0.01` gram-mole ethyelene
[`because`molecular mass of ethylene=28]
(1) Quantity of ethylene in the cylinder=0.01 mol
(2) 1 gram-mole contains `6.022xx10^(23)` ethyelen molecules.
`therefore 0.01` gram-mole contains `6.022xx10^(21)` molecules.
(3) 1 molecules of ethylene `(C_(2)H_(4))` containns 2 carbon atoms.
`therefore 6.022xx10^(21)` molecules of ethylene `(C_(2)H_(4))` contain `2xx6.022xx10^(21)` carbon atoms.
So, the number of carbon atoms present in the cylinder `=2xx6.022xx10^(21)=1.2044xx10^(22)`.