In which mode of expression, the concentration of solution remains independent of temperature ?

Increasing the temperature of an aqueous solution will cause

What is the osmotic pressure of a 0.0020 mol dm^-3 sucrose (C₁₂H₂₂O₁₁) solution at 20^oC ? (Molar gas constant, R = 8.314 JK^-1mol^-1)

Camphor is often used in molecular mass determination because

Low concentration of oxygen in the blood and tissues of people living at high altitude is due to _____________.

Considering the formation, breaking and strength of hydrogen bond, predict which of the following mixtures will show a positive deviation from Raoult's law?

The vapour pressure of a solution of a non - volatile electrolyte (A) in solvent (B) is 95% of the vapour pressure of the solvent at the same temperature. If molar mass of B is 30% of molar mass of A, the mass ratio of the solvent and solute are

A a certain temperature, the value of the slope of the plot of osmotic pressure (\(\pi \) ) against concentration (C in mol L^-1) of a certain polymer solution is 291 R. The temperature at which osmotic pressure is measured is ( R is gas constant)

A solution containing 1.8 g of a compound (empirical formula CH₂O) in 40 g of water is observed to freeze at -0.465^oC. The molecular formula of the compound is (K_f of water = 1.86 kg K mol^-1)

A solution containing 0.10 g of non - volatile solute X (molar mass : 100) in 200 g of benzene depresses the freezing point of benzene by 0.25^oC while 0.50g of another non - volatile solute Y in 100 g of benzene also depresses by 0.25^oC. What is the molecular mass of Y ?

Which will have higher boiling point: 0.1MNaCl or 0.1M, BaCI₂ in water? Explain.

Why is cooking temperature in pressure cooker higher than in the open pan?

Why is the froth flotation method selected for the concentration of sulphide ores?

Name the method used for the refining of Nickel metal.

What is the composition of 'copper matte'?

200 cm³ of an aqueous solution of protein contains 1.26 g of the protein. The osmotic pressure of such a solution at 300 K is found to be 2.57 \(\times\) 10^-3 bar. calculate the molar mass of the protein.

Calculate the mole fraction of ethylene glycol (C₂H₆O₂) in a solution containing 20% of C₂H₆O₂ by mass.

What freezes out first when a solution of common salt is cooled ?

Why is freezing point depression of 0.1 M sodium chloride solution nearly twice that of 0.1 M glucose solution ?

Define the term osmotic pressure. Describe how the molecular mass of substance can be determined by a method based on measurement of osmotic pressure?

State the following:
(i) Raoult's law in its general from in reference to solutions.
(ii) Henry's law about partial pressure of a gas in a mixture.

Why in a concentrated solution, a strong electrolyte shows deviations from Debye-Huckel-Onsager equation ?

Define limiting molar conductivity. Why conductivity of an electrolyte solution decreases with decrease in concentration ?

(i) Following reactions occur at the cathode during the electrolysis of aqueous silver chloride solution:
\({ Ag }^{ + }\left( aq \right) +{ e }^{ - }\rightarrow Ag\left( s \right) \) \({ E }^{ ° }\)=+0.80V
\({ H }^{ + }\left( aq \right) +{ e }^{ - }\rightarrow \frac { 1 }{ 2 } { H }_{ 2 }\left( g \right) \) \({ E }^{ ° }\)=0.00V
On the basis of their standard reduction electrode potential (\({ E }^{ ° }\)) values, which reaction is feasible at the cathode and why?
(ii) Define limiting molar conductivity. Why conductivity of an electrolyte solution decreases with the decrease in concentration?

Two students use same stock solution of ZnSO₄ and a solution of CuSO₄ . The e.m.f. of one cell is 0.03 V higher than the other. The concentration of CuSO₄ in the cell with higher e.m.f. value is 0.5 M. Find out the concentration of CuSO₄ in the other cell (2.303 RT/F = 0.06)

The rate constant for a second order reaction is k = \(\frac {2.303}{t(a-b)} log \frac {b(a-x)}{(b-x)}\)where a and b are initial concentrations of the two reactants A and B involved. If one of the reactants is present in excess, it becomes pseudo unimolecular. Explain how ?

On the basis of ethalpy of formation, graphite is more stable than diamond, yet diamond does not change into graphic for years. Explain why ?

For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained :

Calculate the rate constant.

Is it true that under certain conditions,Mg can reduce SiO₂ and Si can reduce MgO? What are the condition?

The partial pressure of ethane over a saturated 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?

Two liquid X and Y on mixing from an ideal solution. At 30⁰C, the vapour pressure of the solution containing 3 moles of X and 1 mole of Y is 55omm Hg. But when 4 moles of X and 1 mole of Y are mixed,the vapour pressure of the solution thus formed is 560mm Hg. What would be the vapour pressure of pure X and pure Y at this temperature?

When 1.80 g of non-volatile compound is dissolved in 25.0 g of acetone, the solution boils at 56.86°C while pure acetone boils at 56.38°C under the same atmospheric pressure. Calculate the molar mass of the compound. The molal elevation  constant for acetone is 1.72°.

Sliver is electro-deposited on a metalic vessel of surface area 800 cm² by passing a current 0.2 ampere for 3 hours. Calculate the thickness of silver deposited. Given the density of silver as 10.47 g/cc (Atomic mass of Ag = 107.92 amu)

Give reasons for the following :
(i) Alumina is dissolved in cryolite for electrolysis instead of being electrolysed directly.
(ii) Zinc oxide can be reduced to the metal by heating with carbon but not \(Cr_{ 2 }{ O }_{ 3 }\).
(iii) Extraction of copper directly from sulphide ores is less favourable than that from its oxide ore through reduction.

What chemical principle is involved in choosing a reducing agent for getting the metal from its oxide ore? Consider the metal oxides, \(Al_{ 2 }{ O }_{ 3 }\) and \(Fe_{ 2 }{ O }_{ 3 }\), and justify the choice of reducing agent in each case.

Two reactions,
(i) A \(\longrightarrow\) Products
(ii) B \(\longrightarrow\) Products, follow first order kinetics.
The rate of reaction
(i) is doubled when temperature is raised from 300 K to 310 K. The half life for this reaction at 310 K is 30 minutes. At the same temperature, B decomposes twice as fast as A. If the energy of activation for the reaction
(ii) is half that of reaction
(iii), calculate the rate constant of reaction (ii) at 300 K.