SolutionHard
Question
When 36.0 g of a solute having the empirical formula CH2O is dissolved in 1.20 kg of water, the solution freezes at −0.93°C. What is the molecular formula of the solute? (Kf = 1.86°C kg mol−1)
Options
A.C6H12O6
B.C3H6O3
C.CH2O
D.C2H4O2
Solution
$\Delta T_{f} = K_{f}.m \Rightarrow 0.93 = 1.86 \times \frac{36/M}{1.2} \Rightarrow M = 60$
If the molecular formula is CxH2xOx, then
12x + 2x + 16x = 60 ⇒ x = 2
∴ Molecular formula = C2H4O2
Create a free account to view solution
View Solution FreeMore Solution Questions
The vapour pressure of water is 12.3 kPa at 300 K. What is the vapour pressure of 1 molal aqueous solution of a non- vol...Mixture of volatile components A and B has total vapour pressure (in Torr) p = 254 - 119 xA where xA is mole fraction of...The vapour pressure of pure benzene at 88°C is 960 mm and that of toluene at the same temperature is 380 mm of benzene. ...At 4oC, Kw = 1 × 10-16. A solution with pH = 7.5 at 4oC will :-...An azeotropic solution of two liquids has a boiling point lower than either of them when it :...