Oxygen gas generated by the decomposition of potassium chlorate is collected. The volume of oxygen collected at `24^(@)C` and atmospheric pressure of `760 m m Hg` is `128 mL`. Calculate the mass `(` in grams `)` of oxygen gas obtained. The pressure of water vapour at `24^(@)C` is `22.4 m m Hg`.

Options

A. 1.36 g
B. 1.52 g
C. 0.163 g
D. 1.63 g

Answer

c

Explanation

(c) Form the total pressure and the vapour pressure of water we can calculate the partial pressure of `O_(2)`.
`P_(O_(2))=P_(T)-P_(H_(2)O)`
`=760-22.4`
`=737.6 mm " "Hg`
From the ideal gas equation we write
`m=(PVM)/(RT)`
`=((0.974atm)(0.128L)(32.0g//mol))/((0.0821Latm//K mol)(273+24)K)`
`=0.163g`