Question

How many molecules of water are there in 36 g water.......class 9th

Answer 1

water molecular weight=2+16=18
now number of mole =
molar mass/ molecular weight

=
36÷18=2

now
now in 1 mole there are
$6.022 \times {10}^{23}$
molecules
hence in 2 moles there are
$2 \times 6.022 \times {10}^{23} \\ = 1.204 \times {10}^{24}$