Question

Question #ccb14

Answer 1

`0,1833mol`.
`1,104xx10^23` particles.
`71,11%` oxygen by mass.

Explanation:

Moles = Mass divided by molar mass.
`therefore n=(16,5g)/(2xx1+12xx2+16xx4g//mol)=0,1833mol`

One mole contains an Avagadro number of particles, ie `6,023xx10^23` particles.
Hence by ratio and proportion, 0,1833 moles will contain
`0,1833xx6,023xx10^23=1,104xx10^23` particles.

In 1 mole of `H_2C_2O_4`, which has a mass of 90g, exactly 64g of this 90g is oxygen. this corresponds to a percent of `64/90xx100=71,11%`.