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

The two strands in DNA are not identical but are complementary. Explain.

Give two examples to show the anomalous behaviour of fluorine.

Write two uses of ClO₂.

Why are halogens coloured?

Write the reactions of F₂ with water.

With what neutral molecule is ClO⁻ isoelectronic? Is that molecule a Lewis base?

Arrange the following in the order of property indicated for the given set:

HF, HCl, HBr, HI - increasing acid strength.

In terms of band theory, what is the difference between a conductor and an insulator?

In terms of band theory, what is the difference between a conductor and a semiconductor?

Sea is the greatest source of some halogens. Comment.

What happens when 

(i) PCl₅ is heated ? Write the reactions involved.

Give the reason for bleaching action of Cl₂.

Name two poisonous gases which can be prepared from chlorine gas.

How can you prepare Cl₂ from HCl ? Write reaction only.

Write balanced equations for chlorine gas is passed into a solution of NaI in water.

When RNA is hydrolysed, there is no relationship among the quantities of different bases obtained. What does this fact suggest about the structure of RNA?

Account for the following:

Fluorine forms only one oxoacid HOF.

Draw the structures of the following:
(1) HClO₄
(2) H₃PO₃

Draw the structures of the following molecules: BrF₃

ICl is more reactive than I₂.