Question

Calculate the molar mass of a non volatile solute weight 40 grams per mole dissolved in 114 grams of octane to reduce the vapour pressure by 80% p

Answer 1

Answer:

Explanation:

Ps=80% of P0=0.80

Solute =W/40gmol−1

Solvent (octane)=114g/114gmol−1

(molar mass of C8H18=114gmol−1)

Now P0−Ps/P0=x2

∴P0−0.80P0/P0=W/40/W/40+1

Or 0.8W/40=0.2

⇒W=10g