On dissolving 0.25 g of a non-volatile substance in 30 mL benzene (density 0.8 g mL^(-1)) , its freezing point decreases by 0.25^(@)C . Calculate the molecular mass of non-volatile substance (K_(f) = 5.1 K kg mol^(-1)) .

Differentiate between biodegradable and non-biodegradable substances. Give examples.

A solution of a colourles salt H on boiling with excess of NaOH produces a non-flammable gas and the evolution of gas ceases after sometime. Upon addition of Zn dust to the same solution, the evolution of gas restarts. The colourless salt (S) 'H' is (are)

Differentiate between a soluble substance and an insoluble substance.

A solution of colourless salt on boiling with excess NaOH produces a non-flammable gas. The gas evolution ceases after sometime upon addition of Zn dust to the same solution, the gas evolution restarts. The colourless salt (s) is (are).

Give any two ways in which non-biodegradable substances would affect the environment

The vapour pressure of benzene at 80^(@)C is lowered by 10mm by dissoving 2g of a non-volatile substance in 78g of benzene .The vapour pressure of pure benzene at 80^(@)C is 750mm .The molecular weight of the substance will be:

The solution of 2.5 g of a non-volatile substance in 100 g of benzene boiled at a temperature 0.42^(@)C higher than the b.p. of pure benzene. Calculate mol. Wt. of the substance. ( K_(b) of benzene is 2.67 K kg "mole"^(-1) )

Which of the following have hard and non pliable ground substance :-

The vapour pressure of a 5% aqueous solution of a non-volatile organic substance at 373 K . Is 745 mm . Calculate the molecular mass of the solute.