Write lewis structure of the following compounds and show formal charge each atom.

The variation of the vapour pressure of different liquids with temperature is shown in the figure below.

At high altitude, atmospheric pressure is low (say 60 mm Hg). At what temperature will liquid D boil?

Give reasons why hydrogen resembles alkali metals?

Present a comparative account of the alkali and akaline earth metals with respect to the following characteristics.
Nature of oxides and their solubility in water

Three pairs of compounds are given below, Identify that compound in each of the pairs which has group 13 element in more stable oxidation state. Give reason for your choice. State the nature of bonding also.
TlCl₃, TlCl

Consider structure I to VII and answer the following questions (i) and (ii).
I. \({ CH }_{ 3 }-{ CH }_{ 2 }-{ CH }_{ 2 }-{ CH }_{ 2 }-{ OH }\) 
II. \({ CH }_{ 3 }-{ CH }_{ 2 }-{ CH }-{ CH }_{ 3 }\\ \quad \quad \quad \quad \quad \quad \quad |\\ \quad \quad \quad \quad \quad \quad \quad { OH }\)  
III. \({ \quad \quad \quad \quad CH }_{ 3 }\\ \quad \quad \quad \quad |\\ { { CH }_{ 3 } }-{ C }-{ CH }_{ 3 }\\ \quad \quad \quad \quad |\\ \quad \quad \quad \quad { OH }\) 
IV. \({ CH }_{ 3 }-{ CH }-{ CH_{ 2 } }-{ OH }\\ \quad \quad \quad \quad |\\ \quad \quad \quad \quad { CH }_{ 3 }\) 
V. \({ CH }_{ 2 }-{ CH }_{ 2 }-{ O }-{ CH }_{ 2 }-{ CH }_{ 3 }\)
VI. \({ CH }_{ 2 }-{ O }-{ CH }_{ 2 }-{ CH }_{ 2 }-{ CH }_{ 3 }\) 
VII. \({ CH }_{ 3 }-{ O }-{ CH }-{ CH }_{ 3 }\\ \quad \quad \quad \quad \quad \quad |\\ \quad \quad \quad \quad \quad \quad { CH }_{ 3 }\) 
Identify the pairs of compounds that represent position isomerism.

In the presence of peroxide, addition of HBr to propene takes place according to anti-Markownikoff's rule but peroxide effect is not seen in the case of HCl and HI. Explain.

Some time ago formation of polar stratospheric clouds was reported over Antarctica. Why were these formed? What happens when such clouds break up by the warmth of sunlight?