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

Two elements A and B form compounds having formula AB₂ and AB₄. When dissolved in 20 g of benzene (C₆H₆), 1 g of AB₂ lowers the freezing point by 2.3 K whereas 1.0 g of AB₄ lowers it by 1.3 K. The molar depression constant for benzene is 5.1 K kg mol⁻¹. Calculate the atomic masses of A and B.

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.

Calculate the depression in the freezing point of water when 10 g of CH₃CH₂CHClCOOH is added to 250 g of water. K_a = 1.4 × 10⁻³, K_f = 1.86 K kg mol⁻¹.

Suggest two materials other than hydrogen that can be used as fuels in fuel cells.

How are the colloidal solutions classified on the basis of physical states of the dispersed phase and dispersion medium?

Why are hydrophobic sols easily coagulated?

How are colloids classified on the basis of Physical states of components

How are colloids classified on the basis of the nature of the dispersion medium?

How are colloids classified on the basis of interaction between the dispersed phase and the dispersion medium?

Discuss the nature of bonding in metal carbonyls.

Where does the water present in the egg go after boiling the egg?

What is the effect of denaturation on the structure of proteins?

Account for the following:

Diazonium salts of aromatic amines are more stable than those of aliphatic amines.

Predict the product of the following reaction:

\[\ce{CH3 - CH2 - CH2 - O - CH3 + HBr ->}\]

Predict the product of the following reaction:

Predict the product of the following reaction:

\[\ce{(CH3)3C - OC2H5 ->[HI]}\]

Show how will you synthesize cyclohexylmethanol using an alkyl halide by an S_N2 reaction.

Write the equation of the reaction of hydrogen iodide with 1-propoxypropane.

Write the equation of the reaction of hydrogen iodide with methoxybenzene.

Write the equation of the reaction of hydrogen iodide with benzyl ethyl ether.