List of practice Questions

Use molecular orbital theory to explain why the \(Be_2\) molecule does not exist.

What is stomatal apparatus? Explain the structure of stomata with a labelled diagram.

Explain the formation of \(H_2\) molecule on the basis of valence bond theory.

Draw a neat diagram of digestive system of frog.

Distinguish between a sigma and a pi bond.

If the velocity of the electron in Bohr’s first orbit is 2.19×10⁶ms^–1, calculate the de Broglie wavelength associated with it.

What do you understand by bond pairs and lone pairs of electrons? Illustrate by giving one example of each type.

Which hybrid orbitals are used by carbon atoms in the following molecules? 

1. \(CH_3-CH_3\); 
2. \(CH_3-CH=CH_2\); 
3. \(CH_3-CH_2-OH\); 
4. \(CH_3-CHO\) 
5. \(CH_3COOH\)

Name two cell-organelles that are double membrane bound. What are the characteristics of these two organelles? State their functions and draw labelled diagrams of both.

Similar to electron diffraction, a neutron diffraction microscope is also used for the determination of the structure of molecules. If the wavelength used here is 800 pm, calculate the characteristic velocity associated with the neutron.

What is the total number of sigma and pi bonds in the following molecules?

1. \(C_2H_2\) 
2. \(C_2H_4\)

Is there any change in the hybridisation of B and N atoms as a result of the following reaction? 
\(BF_3+ NH_3 \rightarrow F_3B.NH_3\)

A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.

1. What is the initial effect of the change on vapour pressure?
2. How do rates of evaporation and condensation change initially?
3. What happens when equilibrium is restored finally and what will be the final vapour pressure?

K_p = 0.04 atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of C₂H₆ when it is placed in a flask at 4.0 atm pressure and allowed to come to equilibrium?
\(C_2H_6 (g) ⇋ C_2H_4 (g) + H_2 (g)\)

Find \(\frac {dy}{dx}\): \(2x+3y=sin\ x\)

Find \(\frac {dy}{dx}\): \(xy+y^2=tan\ x+y\)

Find \(\frac {dy}{dx}\): \(x^2+xy+y^2=100\)

Find \(\frac {dy}{dx}\): \(x^3+x^2y+xy^2+y^3=81\)

What is the equilibrium concentration of each of the substances in the equilibrium when the initial concentration of \(ICl\) was \(0.78 \ M\)?
\(2ICl (g) ⇋ I_2 (g) + Cl_2 (g); \ K_c = 0.14\)

One mole of H₂O and one mole of CO are taken in 10 L vessel and heated to 725 K. At equilibrium 40% of water (by mass) reacts with CO according to the equation,
\(H_2O (g) + CO (g) ⇋ H_2 (g) + CO_2 (g)\)
Calculate the equilibrium constant for the reaction.

Dual behaviour of matter proposed by de Broglie led to the discovery of electron microscope often used for the highly magnified images of biological molecules and other type of material. If the velocity of the electron in this microscope is 1.6 × 106 ms–1, calculate de Broglie wavelength associated with this electron.

Calculate the wavelength for the emission transition if it starts from the orbit having radius of 1.3225 nm and ends at 211.6 pm. Name the series to which this transition belongs and the region of the spectrum.

Explain the composition of triglyceride.

Emission transitions in the Paschen series end at orbit n = 3 and start from orbit n and can be represented as v = 3.29 × 10¹⁵ (Hz) [\(\frac{1}{3^2}-\frac{1}{n^2}\)] Calculate the value of n if the transition is observed at 1285 nm. Find the region of the spectrum.

Can you attempt building models of biomolecules using commercially available atomic models (Ball and Stick models).