Question

Find the mass of 10 moles of sodium sulphite `(Na_(2)SO_(3))`
(b)Calculate the number of molecules in 8g of oxygen gas.
(c )Convert 22g of `CO_(2)` into moles.

Answer 1

`"Molar mass of "Na_(2)SO_(3)=2xx23+32+3xx16`
`=46+32+48=126g`
`"Mass of 10 moles of "Na_(2)SO_(3)=126xx10=1260g`
(b)=Molar mass of oxygen `(O_(2))`=32g
Molar mass of `(O_(2))`=32g
32g of oxygen=1 mol
8g of oxygen`=(1"mol")xx((8g))/((32g))=0.25"mol"`
(c )`"Molar mass of "CO_(2)=12+2xx16=44g`
44g of `CO_(2)`=1 mol
22g of `CO_(2)=(1"mol")xx((22g))/((44g))=0.5"mol"`