Question

Calculate the number of molecules in a 45.6 gram sample of C2H4.

Answer 1

Answer: The number of molecules in a 45.6 gram sample of
`C_(2)H_(4)` are
`9.78 * 10^(23)`.

Step-by-step explanation:

Given: Mass of
`C_(2)H_(4)` = 45.6 g

Molar mass of
`C_(2)H_(4)` is 28.05 g/mol.

Therefore, number of moles of
`C_(2)H_(4)` are calculated as follows.

`No. of moles = (mass)/(molarmass)\\= (45.6 g)/(28.05 g/mol)\\= 1.62 mol`

According to the mole concept, 1 mole of every substance contains
`6.022 * 10^(23)` molecules. Hence, number of molecules present in 1.62 mol are calculated as follows.

`1.62 * 6.022 * 10^(23)\\= 9.78 * 10^(23)`

Thus, we can conclude that the number of molecules in a 45.6 gram sample of
`C_(2)H_(4)` are
`9.78 * 10^(23)`.