500 mL of `NH_(3)` contain `6.00xx10^(23)` molecules at a certain temperature and pressure. How many molecules are present in 100 mL of `CO_(2)` at same temperature and pressure?

Options

A. `6xx10^(23)`
B. `1.5xx10^(21)`
C. `1.2xx10^(23)`
D. None of these

Answer

C

Explanation

Under similar conditions of temperature and pressure equal volume of different gases contain equal number of molecules
`:.` if 500 mL of `CO_(2)` contain `6.00xx10^(23)` molecules
`:.` 100 mL of `CO_(2)` will contain
`=(6.00xx10^(23))/(500)xx100`
`=1.2xx10^(23)` molecules