Class 11 - Chemistry
Predict the shapes of the following molecules using VSEPR theory?
(i) BeCl2(ii) SiCl4
Questions and Answers
Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.
Write Lewis symbols for the following atoms and ions: S and S2– ; Al and Al3+; H and H–
Draw the Lewis structures for the following molecules and ions:
H2S, SiCl4 , BeF2, C032-, HCOOH
Define Octet rule. Write its significance and limitations.
Write the favourable factors for the formation of ionic bond.
Discuss the shape of the following molecules using the VSEPR model:
BeCl2, BCl3 , SiCl4, AsF5, H2S, PH3
Although geometries of NH3 and H20 molecules are distorted tetrahedral, bond angle in water is less than that of ammonia. Discuss.
How do you express the bond strength in terms of bond order?
Define the bond-length.
Explain the important aspects of resonance with reference to the C032-ion.
Write the resonance structures for SO3,NO2 and NO3
Use Lewis symbols to show electron transfer between the following atoms to form cations and anions (a) K and S (b) Ca and O (c) Al and N.
Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2 is linear. Explain this on the basis of dipole moment.
Write the significance/applications of dipole moment.
Define electronegativity. How does it differ from electron gain enthalpy?
Explain with the help of suitable example polar covalent bond.
Arrange the bonds in order of increasing ionic character in the molecules: LiF, K2O, N2, SO2 and ClF3.
The skeletal structure of CH3COOH as shown below is correct, but some of the bonds are shown incorrectly. Write the correct Lewis structure for acetic acid.
Apart from tetrahedral geometry, another possible geometry for CH4 is square planar with the four H atoms at the comers of the square and the C atom at its centre. Explain why CH4 is not square planar?
Explain why BeH2 molecule has a zero dipole moment although the Beâ€”H bonds are polar.
Which out of NH3 and NF3 has higher dipole moment and why?
What is meant by hybridisation of atomic orbitals? Describe the shapes of sp, sp2, sp3 hybrid orbitals.
Describe the change in hybridisation (if any) of the Al atom in the following reaction. AlCl3 + Cl– ——>AlCl4- .
Is there any change in the hybridisation ofB and N atoms as a result of the following reaction ? BF3 + NH3 ——-> F3 B.NH3
Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in C2 H4 and C2 H2 molecules.
What is the total number of sigma and pi bonds in the following molecules?
(a) C2 H2 (b) C2 H4
What do you understand by bond pairs and lone pairs of electrons? Illustrate by giving one example of each type.
Distinguish between a sigma bond and a pi bond.
Explain the formation of H2 molecule on the basis of valence bond theory.
Write the important conditions required for the linear combination of atomic orbitals to form molecular orbitals.
Compare the relative stability of the following species and indicate their magnetic properties: O2, O2, O2– (Superoxide),O22- (peroxide)
Write the significance of plus and minus sign in representing the orbitals,
Describe the hybridisation in case of PCl5. Why are the axial bonds longer as compared to equatorial bonds?
Define hydrogen bonds. Is it weaker or stronger than the van der Waals forces?
What is meant by the term bond order? Calculate the bond order of N2, O2, O2+,O2–
How is bond order related to the stability of a molecule?
Write the type of hybridisation involved in CH4,C2H4 and C2H2.
Out of sigma and Î bonds, which one is stronger and why?
Write the Lewis dot symbols of the following elements and predict their valencies. (i) Cl (ii) P
Write the state of hybridisation of boron in BF3.
Arrange O2,O2–,O22-, O2+in increasing order of bond energy.
What is meant by bond pairs of electrons?
Define covalent bond according to orbital concept?
Why B2 is paramagnetic in nature while C2 is not?
Why ethyl alcohol is completely miscible with water?
Which is more polar CO2 or N2O? Give reason.
Why N2 is more stable than O2? Explain on the basis of molecular orbital theory.
How is bond order related to bond length of a molecule?
Define antibonding molecular orbital.
Name the two conditions which must be satisfied for hydrogen bonding to take place in a molecule.