Question

A sample of `O_(2)` is collected over water at `22^(@)C` and 748 torr pessure. The volume of the gas collected is 82.0 `cm^(3)`. How many grams of oxygen are present in the gas?. The valour pressure of water at `22^(@)C` is 19.8 torr.

Answer 1

`p_(O_(2))=748-19.8=728.2` torr
`=(728.2)/(760)atm=0.958atm`
`V=82cm^(3)=82xx10^(-3)L`
`n=(PV)/(RT)`
`=(0.958(atm)xx82xx10^(-3)(L))/(0.0821("atm "LK^(-1)mol^(-1))xx295.15(K))`
Mass of `O_(2)=3.24xx10^(-3)(mol)xx32(g mol^(-1))` ltbr. `=0.1036=0.104g`