PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Chemistry

What is the coordination number of atoms in a cubic close-packed structure?

How can you determine the atomic mass of an unknown metal if you know its density and the dimension of its unit cell? Explain.

H₂S, a toxic gas with rotten egg like smell, is used for the qualitative analysis. If the solubility of H₂S in water at STP is 0.195 m, calculate Henry’s law constant.

Henry’s law constant for CO₂ in water is 1.67 × 10⁸ Pa at 298 K. Calculate the quantity of CO₂ in 500 mL of soda water when packed under 2.5 atm CO₂ pressure at 298 K.

The partial pressure of ethane over a solution containing 6.56 × 10⁻³ g of ethane is 1 bar. If the solution contains 5.00 × 10⁻² g of ethane, then what shall be the partial pressure of the gas?

Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain.

Cyclohexane, KCl, CH₃OH, CH₃CN

Identify that the following compound is insoluble, partially soluble or highly soluble in water:

pentanol

Henry’s law constant for the molality of methane in benzene at 298 K is 4.27 × 10⁵ mm Hg. Calculate the solubility of methane in benzene at 298 K under 760 mm Hg.

The air is a mixture of a number of gases. The major components are oxygen and nitrogen with approximate proportion of 20% is to 79% by volume at 298 K. The water is in equilibrium with air at a pressure of 10 atm. At 298 K if the Henry’s law constants for oxygen and nitrogen are 3.30 × 10⁷ mm and 6.51 × 10⁷ mm respectively, calculate the composition of these gases in water.

Calculate the potential of hydrogen electrode in contact with a solution whose pH is 10.

Calculate the emf of the cell in which the following reaction takes place: 

\[\ce{Ni_{(s)} + 2Ag^+ (0.002 M) -> Ni^{2+} (0.160 M) + 2Ag_{(s)}}\]

Given that \[\ce{E^Θ_{cell}}\] = 1.05 V

What is the significance of leaching in the extraction of aluminium?

How can you separate alumina from silica in a bauxite ore associated with silica? Give equations, if any.

How is leaching carried out in case of low grade copper ores?

What are the different oxidation states exhibited by the lanthanoids?

Compare the chemistry of actinoids with that of lanthanoids with special reference to electronic configuration.

Compare the chemistry of actinoids with that of the lanthanoids with special reference to oxidation state.

Compare the chemistry of actinoids with that of the lanthanoids with special reference to atomic and ionic sizes.

Compare the chemistry of actinoids with that of the lanthanoids with special reference to chemical reactivity.

The chemistry of the actinoid elements is not so smooth as that of the Lanthanoids. Justify this statement by giving some examples from the oxidation state of these elements.