Calculate the amount of benzoic acid (\(C_{6}H_{5}COOH\)) required for preparing 250 mL of 0.15 M solution in methanol.

Two elements \(A\) and \(B\) form compounds having formula \(AB_{2}\) and \(AB_{4}\). When dissolved in 20 g of benzene (\(C_{6}H_{6}\)), 1 g of \(AB_{2}\) lowers the freezing point by 2.3 K whereas 1.0 g of \(AB_{4}\) lowers it by 1.3 K. The molar depression constant for benzene is 5.1 K kg \(mol^{-1}\). Calculate atomic masses of \(A\) and \(B\).

Vapour pressures of pure acetone and chloroform at 328 K are 741.8 mm Hg and 632.8 mm Hg respectively. Assuming that they form ideal solution over the entire range of composition, plot \(p_{total}\), \(p_{chloroform}\), and \(p_{acetone}\) as a function of \(x_{acetone}\). The experimental data observed for different compositions of mixture is: 

Plot this data also on the same graph paper. Indicate whether it has positive deviation or negative deviation from the ideal solution.

Define the following terms:
(iv) Mass percentage.

Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is 1.504 g \(mL^{-1}\)?

A 5% solution (by mass) of cane sugar in water has freezing point of 271K. Calculate the freezing point of 5% glucose in water if freezing point of pure water is 273.15 K.

Amongst the following compounds, identify which are insoluble, partially soluble and highly soluble in water?
(iv) ethylene glycol

A sample of drinking water was found to be severely contaminated with chloroform (\(CHCl_{3}\)) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass):
(ii) determine the molality of chloroform in the water sample.

An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar at the normal boiling point of the solvent. What is the molar mass of the solute?

The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.

If the density of some lake water is 1.25g \(mL^{-1}\) and contains 92 g of \(Na^{+}\) ions per kg of water, calculate the molarity of \(Na^{+}\) ions in the lake.

Suggest the most important type of intermolecular attractive interaction in the following pairs.
(ii) \(I_{2}\) and \(CCl_{4}\)

Define the following terms:
(i) Mole fraction

A sample of drinking water was found to be severely contaminated with chloroform (\(CHCl_{3}\)) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass):
(i) express this in percent by mass

Suggest the most important type of intermolecular attractive interaction in the following pairs.
(iv) methanol and acetone

19.5 g of \(CH_{2}FCOOH\) is dissolved in 500 g of water. The depression in the freezing point of water observed is 1.00 C. Calculate the van’t Hoff factor and dissociation constant of fluoroacetic acid.

If the solubility product of CuS is \(6 \times 10^{-16}\), calculate the maximum molarity of CuS in aqueous solution.

Calculate the depression in the freezing point of water when 10 g of \(CH_{3}CH_{2}CHClCOOH\) is added to 250 g of water. \(K_{a} = 1.4 \times 10^{-3}\), \(K_{f} = 1.86\) K kg \(mol^{-1}\).

The partial pressure of ethane over a solution containing \(6.56 \times 10^{-3}\) g of ethane is 1 bar. If the solution contains \(5.00 \times 10^{-2}\) g of ethane, then what shall be the partial pressure of the gas?

Define the term solution. How many types of solutions are formed? Write briefly about each type with an example.