Question

18 gram of sucrose is dissolved in 180 gram of water. Calculate the number of oxygen atoms in the solution.​

answer: 6.684×10^24

Answer 1

We know, molecular mass of sucrose is 342 g/mol.

So, number of moles in 18 g is :

`n_1 = (342\ g/mol)/(18\ g)\\\\n_1 = 0.053 \ moles`

Also, number of moles of water is :

`n_2 = (180)/(18) \\\\n_2 = 10 \ moles`

We know, 1 mole of sucrose contain 11 moles of oxygen.

So,

`n' = 0.053* 11\\\\n'= 0.583\ moles`

1 mole of water contain 1 mole of oxygen .

So, moles of oxygen in water are :

`n'' = 10\ moles`

Total number of moles,
`n' + n'' = 10.583 \ moles` .

Number of oxygen atoms are :

`N = 6.022 * 10^(23)* 10.583\\\\N = 6.37 * 10^(24)`

Hence, this is the required solution.