HSC Science Class 11 - Tamil Nadu Board of Secondary Education Question Bank Solutions for Chemistry

The partial pressure of nitrogen in air is 0.76 atm and its Henry’s law constant is 7.6 × 10⁴ atm at 300 K. What is the mole fraction of nitrogen gas in the solution obtained when air is bubbled through water at 300 K?

Which one of the following is incorrect for an ideal solution?

Define Hess's law of constant heat summation.

The K_H for the solution of oxygen dissolved in water is 4 × 10⁴ atm at a given temperature. If the partial pressure of oxygen in air is 0.4 atm, the mole fraction of oxygen in solution is ______.

Two liquids X and Y on mixing gives a warm solution. The solution is ______.

The mass of a non – volatile solute (molar mass 80 g mol^-1) should be dissolved in 92g of toluene to reduce its vapour pressure to 90% ______.

Assertion: An ideal solution obeys Raoults Law.

Reason: In an ideal solution, solvent – solvent as well as solute – solute interactions are similar to solute-solvent interactions.

State Raoult law and obtain the expression for lowering of vapour pressure when the nonvolatile solute is dissolved Insolvent.

Which solution has the lower freezing point? 10 g of methanol (CH₃OH) in 100g g of water (or) 20 g of ethanol (C₂H₅OH) in 200 g of water.

The observed depression in the freezing point of water for a particular solution is 0.093°C calculate the concentration of the solution in molality. Given that molal depression constant for water is 1.86 K Kg mol^-1.

Ortho and para – nitro phenol can be separated by ______.

The purity of an organic compound is determined by ______.

A liquid which decomposes at its boiling point can be purified by ______.

Assertion: \[\begin{array}{cc}
\ce{CH - C = CH - COOH}\\|\phantom{.}\\
\phantom{........}\ce{COOC2H5}\end{array}\]

Reason: The principal functional group gets lowest number followed by double bond (or) triple bond. 

Give a brief description of the principles of Fractional distillation.

Give a brief description of the principle of column Chromatography.

Explain paper chromatography.

Osomotic pressure (π) of a solution is given by the relation

The bond dissociation energy of methane and ethane are 360 kJ mol^–1 and 620 kJ mol^–1 respectively. Then, the bond dissociation energy of the C-C bond is

What is lattice energy?