Question

how many molecules of water and oxygen atoms are present in 0.9 gram of water
explain briefly
without mistake

Answer 1

Molecular mass of H2O = 18g/mol

Numbers of molecules present in 18g of H2O =6.022×10^23 molecules

Numbers of molecules present in 0.9g of

H2O = 6.022×10^23×18×0.9 molecules

Numbers of atom in 1 molecule 3(2hydrogen and 1 oxygen)

Number of atoms in

6.022×10^23×18×0.9 molecules of

H2O =

6.022×10^23×0.9×3

= 9.03×10^22 atoms.

Hope this helps you ☺️☺️❤️❤️✌️✌️

Answer 2

Gram molar mass of water =18g

Number of
moles in 0.9 grams of water

$= \frac{18}{0.9} = 0.05$

Number of water molecules in 1 mole of water

$= 6.023 \times {10}^{23}$

Number of molecules of water in 0.05 moles

$= 0.05 \times 6.023 \times {10}^{23} = 3.010 \times {10}^{22}$

As one molecule of water contains one oxygen atom

So the number of oxygen atom in
$3.010 \times {10}^{22} \\ molecules \: of \: water = 3.010 \times {10}^{22}$