Question

the vapour pressure of 5% aqueous solution of a non-volatile organic substance at 373K is 745mm Hg. calculate the molar mass of the substance . With calculation please!

Answer 1

5 % aqueous solution of the solute means that 5g of the solute are present in 100 g of the solution

(i.e) Weight of Solute (w2)=5g(w2)=5g

Weight of solution =100 g

weight of solvent (w1)=100−5=95g(w1)=100−5=95g

Further as the solution in aqueous , it means that the solvent is water and we know that

Vapour pressure of pure water at 373K(p0)=760mm373K(p0)=760mm

Vapour pressure of solution at 373.k(Ps)=745mm373.k(Ps)=745mm

Molecular mass of solvent (water ).M1=18M1=18

Molecular mass of solute M2M2 = to be calculated

Using the formula for dilute solution ,

M2=w2×M1(p0)wt(po−Ps)M2=w2×M1(p0)wt(po−Ps)

M2=5×18×76095×(760−745)M2=5×18×76095×(760−745)

M2=684001425M2=684001425=48

Answer 2

Answer:

Explanation:hope help u