500mL of `NH_(3)` contains `6.02xx10^(23)` molecules at STP. How many molecules are present in 100 mL of `CO_(2)` at STP?

Options

A. `6xx10^(23)`
B. `1.5xx10^(23)`
C. `1.2xx10^(23)`
D. None of these

Answer

C

Explanation

`Vpropn`
`V_(1)/n_(1)=V_(2)/n_(2):.500/1=100/n_(2)`
`n_(2) =1/5` mole [ 1mole =6.023 `xx 10^(23)` molecule]
`n_(2)=1/5 xx6.023 xx 10^(23)=1.2 xx 10^(23)`