Question

calculate the number of moles and molecules of urea prent in 8.2g of urea​

Answer 1

Answer:

18.2 g of urea is dissolved in 100g of water at 50oC. The lowering of vapour pressure produced is 5 mm Hg. Calculate the molecular mass of urea. The vapour pressure of water at 50oC is 92 mm Hg.

We have,

PB0PBo−Pt=xA

925=nA+nBnA = x+5.55x

 we get x = 0.316 moles

 molecular weight = molesweight 

 molecular weight of urea = 57.05