InterviewSolution
Saved Bookmarks
| 1. |
For a dilute solution containing 2.5g of a non-volatile non-electrolyte solute in 100g of water, the elevation in boiling point at 1 atm pressure is `2^(@)"C"`. Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressure (mm of Hg) of the solution is (take `K_(b)`=0.76 K kg `"mol"^(-1)`)A. 724B. 740C. 736D. 718 |
|
Answer» Correct Answer - A `DeltaT=K_(b)xxm` `2=0.76xxm` `m=(2)/(0.76)=2.63` Mole fraction of solute can be calculated as `m=(x_(B)xx1000)/((1-x_(B))m_(A))` `2.63=(x_(B)xx1000)/((1-x_(B))xx18)` `x_(B)=0.045` `(p_(0)-p)/(p_(0))=x_(B)` `(760-p)/(760)=0.045` or `p=725.8` mm It is close to 724 mm] |
|