(A)The mass of one molecule of a substance is `4.65xx10^(-23)g`. What is its molecular mass? What could be substance be?
(b)Which have more molecules? 10g of sulphur dioxide `(SO_(2))` or 10g of oxygen `(O_(2))`?

Explanation

(a) Mass of one molecules of substance =`4.65xx10^(-23g)`
`"Mass of "6.022xx10^(23)"molecules of substance"=6.022xx10^(23)xx(4.65xx10^(-23))=28g`
The substances can be carbon monoxide (CO) with molecular mass=12+16=28u or 28g
(b) `"Molar mass of "SO_(2)=32h+2xx16g=64g`
`"64g of sulphur dioxide represent molecules"=6.022xx10^(23)`
`"10g of sulphur dioxide represent molecules"=(6.022xx10^(23)xx(10g))/((64g))=9.40xx10^(22)`
`"Molar mass of oxygen "(O_(2))=32g `
32g of oxygen represent molecules =`6.022xx10^(23)`
`"10g of oxygen represent molecules"=(6.022xx10^(23)xx(10g))/((32g))=1.88xx10^(23)`