Solutions Test ...

For the equilibrium, $$CH_3-CH_2-CH_2-CH_3(g)\leftrightharpoons CH_3-CH(CH_3)-CH_3(g)$$
                                                                                                 isobutane
If the value of $$ K_c$$ is $$3.0, $$ the percentage by mass of iso-butane in the equilibrium mixture would be :

At $${40^ \circ }C$$ the vapour pressure ( in torr ) of a mixture of methyl alcohol and ethyl alcohol is represented by $$P = 199x + 135$$
(where $$x$$ is the mole fraction of methyl alcohol) 

The vapour pressure of a solvent decreases by $$10\ mmHg$$ when a non-volatile solute was added to the solvent. The mole fraction of the solute in the solution is 0.2. If the decrease in vapour pressure is $$20\ mmHg$$ then the mole fraction of the solvent is:

A mixture of 50.ml of $$N{H_3}$$ and 60.0 ml of $${O_2}$$ gas react as
$$4N{H_3}(g) + 5{O_2}(g)\xrightarrow{{}}4NO + 6{H_2}O(g)$$
If all the gases are at the same temperature and the reaction continues until one of the gases is completely consumed, what volume of water vapour is produced?

Which of the following pairs shows ideal behaviour?

Calculate the mass of a non - volatile solute (molar  mass $$40\,\,g mol^{-1}$$) which should be dissolved in $$114g$$ octane to reduce its vapour pressure to $$80\%$$

50 mL of 1 M oxalic acid(molar mass = 126 g) is shaken with 0.5 g of wood charcoal, the final concentration of the solution after adsorption is 0.5 M. Calculate the amount of oxalic acid adsorbed per gram of charcoal.

Which of the following solutions will have the lowest vapour pressure?

The vapour pressure of two volatile liquid mixtures is $$P_T =5.3+2X_B$$ (in mm of Hg), where $$X_B$$ is mole fraction of B in mixture. What is the ratio of mole fractions of A & B in liquid phase.
( $$P_A \ and\  P_B$$ are vapour pressures of A & B) 

Which of the following has maximum Van't hoff 's factor?