19.

20.
21.
22.

23.

24.
25.
26.

30.

31,

How is XeF, prepared ?

How would you account for the different colours produced by alkaline earth metals in the Buns

flame ?

Explain the term polarisation of an anion

Discuss the variation of oxidation states of eleménts as we move from left to right in a period

What are Pseudohalides ?

Section C

Answer any five questions.
Each question carries 6 marks.

Discuss the general trends in Group I with respect to :

(i) Melting point. (ii) Density.

(111) Ionisation energy. (iv) Atomic and Ionic radii

Write SN on co-precipitation.

(10 x 2 = 20 marks

How are determinate and indeterminate errors classified ? How are they detected and corrected ?

Discuss the gradation in properties of elements of group 13 with respect to (a) electron affinity ;

(b) metallic character.

. What are Carbides ? How do we classify them ?
28.
29.

What is thermal] pollution ?

What are the limitations of liquid ammonia 89 ೫೦1೪೮೧೪? |

What is meant by the terms~sample, sample population and population mean ? How are sample

mean and population mean determined ?

Section D

‘Answer any two questions.
Each question carries 10 marks.

(5 x 6 = 30 marks)

(a) What is Smog ? What is the difference between classical smog and photochemical smog?

What are the adverse effects of photochemical smog?

(b) Write S.N. on green house effect.

(6 marks)
(4 mark?)