Dimethyl ether has larger bond angle than water. This is because there is more repulsion between bond pairs of CH3 groups attached in ether than between bond pairs of hydrogen atoms attached to oxygen in water. The carbon of CH3 group in ether is attached to three hydrogen atoms through c bonds and electron pairs of these bonds add to the electron charge density on carbon atom. Hence, repulsion between two -CH3 groups will be more than that between two H atoms.
Match the species in Column I with the geometry/shape in Column II.
Column I | Column II |
(i) H30+ | (a) Linear |
(ii) HC = CH | (b) Angular |
(iii) Cl0–2 | (c) Tetrahedral |
(iv) NH+4 | (d) Trigonal bipyramidal |
– | (e) Pyramidal |
Which of the following statements are correct about CO32- ?
(a) The hybridization of central atom is sp3.
(b) Its resonance structure has one C – O single bond and two C = O double bonds.
(c) The average formal charge on each oxygen atom is 0.67 units.
(d) All C – O bond lengths are equal.
Match the shape of molecules in Column I with the type of hybridization in Column II.
Column I | Column II |
(i) Tetrahedral | (a) sp2 |
(ii) Trigonal | (b) sp |
(iii) Linear | (c) sp3 |
Account for the following:
(i) Water is a liquid while H2S is a gas
(ii) NH3 has higher boiling point than PH3.
In which of the following substances will hydrogen bond be strongest?
(a) HCl
(b) H20
(c) HI
(d) H2S
Using molecular orbital theory, compare the bond energy and magnetic character of 0+2 and O–2
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.
Which hybrid orbitals are used by carbon atoms in the following molecules?
(a) CH3-CH3 (b) CH3-CH = CH2 (c) CH3-CH2-OH (d) CH3-CHO (e) CH3COOH.
Name the two conditions which must be satisfied for hydrogen bonding to take place in a molecule.
3PO3 can be represented by structures 1 and 2 shown below. Can these two structures be taken as the canonical forms of the resonance hybrid representing H3PO3? If not, give reasons for the same.
(a) How many a and n bonds are present in
(b) Why Hf is more stable than H2?
(c) Why is B2 molecule paramagnetic?
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- .
Draw diagrams showing the formation of a double bond and a triple bond between carbon atoms in C2 H4 and C2 H2 molecules.
Explain the diamagnetic behaviour of P2 molecule on the basis of molecular orbital theory.
What is an ionic bond? With two suitable examples explain the difference between an ionic and covalent bond?
Predict the shapes of the following molecules on the basis of hybridization. BC13, ch4, co2, nh3
Match the species in Column I with the type of hybrid orbitals in Column II.
Column I | Column II |
(i) SF4 | (a) sp3cf |
(ii) if5 | (b) d2sp3 |
(iii) NO2+ | (c) sp3 d |
(iv) NH4 | (d) sp3 |
(e) sp |
Match the species in Column I with the bond order in Column II.
Column I | , . Column II |
(i) NO | (a) 1.5 |
(ii) CO | (b) 2.0 |
(iii) o–2 | (c) 2.5 |
(iv) 02 | (d) 3.0 |
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.
(a) Define dipole moment. What are the units of dipole moment?
(b) Dipole moment values help in predicting the shapes of covalent molecules. Explain.
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 atoms at its centre. Explain why CH4 is not square planar?
In N0–3 ion, the number of bond pairs and lone pairs of electrons on nitrogen atom are
(a) 2, 2 (b) 3, 1 (c) 1,3 (d) 4, 0
Explain the non linear shape of H2S and non planar shape of PCl3 using valence shell electron pair repulsion theory.
Why does type of overlap given in the following figure not result in the bond formation?