“Value Addition with Training”

UNIT – 4 (CHEMICAL BONDING AND MOLECULAR STRUCTURE)

Q1. Ice floats on water. Rishabh asked his teacher, why ice is lighter than water? The teacher explained

the phenomenon to Rishabh and He got satisfied.

(i) What would be the answer of the teacher?

(ii) What is the hydrogen bond or hydrogen bonding?

(iii) What values are displayed by Rishabh?

Q2. Two students Saloni and Aditi were discussing about the allotropes of carbon. Saloni asked Aditi

,why one allotrope of carbon is very hard use to make jewellery meanwhile Aditi told Saloni that other

allotrope of carbon is a good conductor and used to make pencils.

(i) Name the above two allotropes of carbon.

(ii) Why one allotrope is conductor and other is not?

(iii) What are allotropes?

(iv) What values are associated with these allotropes?

Q3. The Chemistry teacher was explaining the properties of two hydrides of Sulphur and Oxygen: H2S

and H2O.

H2S and H2O are having same hybridization states but different bond angles. H2S have indefinite volume

while H2O has definite volume. H2S cannot be placed in an open container but H2O can be placed

due to their different physical states.

(i) Write the hybridization states of central atom in H2S and H2O.

(ii) What are the physical states of H2S and H2O?

(iii) Write bond angle of H2O.

(iv) Why H2S and H2O have different bond angles?

(v) Draw the Lewis structures of both the hydrides.

Q4. Rishabh and Sejal were discussing the difference between NF3 and NH3 and both got confused.

Rishabh and Sejal asked their subject teacher, why NF3 and NH3 have different dipole moment while

both are having same hybridization states and same number of lone pair of electrons.

Downloaded from www.studiestoday.com

Downloaded from www.studiestoday.com

Downloaded from www.studiestoday.com

Downloaded from www.studiestoday.com