Find the number of hydrogen and oxygenn atoms present in 0.09 g of water.

Explanation

0.09 g water `(0.09)/(18)=5xx10^(-3)` gram-mole of water [`because` molecular mass of water=18]
Number of molecules inn 1 gram-mole water=`6.022xx10^(23)`
`therefore`Number of molecules in `5xx10^(-3)` gram-mole water
`6.022xx10^(23)xx5xx10^(-3)=3.011xx10^(21)`
The number of hydrogen and oxyge atoms in 1 molecule of water `(H_(2)O)` are 2 and 1 respectively.
`therefore`The number of hydrogen atoms in 3.011`xx10^(21)` number of water molecules`=2xx3.011xx10^(21)=6.022xx10^(21)`
`therefore`The number of oxygen atoms`=1xx3.011xx10^(21)`
`=3.011xx10^(21)`