Science (English Medium) Class 11 - CBSE Question Bank Solutions for Chemistry

Which of the following statements is incorrect?

The pH of neutral water at 25°C is 7.0. As the temperature increases, ionisation of water increases, however, the concentration of \[\ce{H+}\] ions and \[\ce{OH-}\] ions are equal. What will be the pH of pure water at 60°C?

On the basis of Le Chatelier principle explain how temperature and pressure can be adjusted to increase the yield of ammonia in the following reaction.

\[\ce{N2 (g) + 3H2 (g) ⇌ 2NH3 (g) ∆H = - 92.38 kJ mol^{-1}}\]

What will be the effect of addition of argon to the above reaction mixture at constant volume?

Why is hydrogen peroxide stored in wax-lined bottles?

Assertion (A): Some metals like platinum and palladium, can be used as storage media for hydrogen.

Reason (R): Platinum and palladium can absorb large volumes of hydrogen.

Sodium forms a crystalline ionic solid with dihydrogen. The solid is nonvolatile and non-conducting in nature. It reacts violently with water to produce dihydrogen gas. Write the formula of this compound and its reaction with water. What will happen on electrolysis of the melt of this solid.

Quartz is extensively used as a piezoelectric material, it contains ______.

In which of the following compounds the carbon marked with asterisk is expected to have greatest positive charge?

Ionic species are stabilised by the dispersal of charge. Which of the following carboxylate ion is the most stable?

Identify the most stable species in the following set of ions giving reason:

\[\ce{\overset{+}{C}H3, \overset{+}{C}H2Br, \overset{+}{C}HBr2, \overset{+}{C}Br3}\]

Identify the most stable species in the following set of ions giving reason:

\[\ce{\overset{Θ}{C}H3, \overset{Θ}{C}H2Cl, \overset{Θ}{C}HCl2, \overset{Θ}{C}Cl3}\]

Give three points of differences between inductive effect and resonance effect.

What is the maximum number of emission lines when the excited electron of an H atom in n = 6 drops to the ground state?

The energy associated with the first orbit in the hydrogen atom is - 2.18 × 10^-18 J atom^-1. What is the energy associated with the fifth orbit?

Calculate the radius of Bohr’s fifth orbit for hydrogen atom

What is the energy in joules, required to shift the electron of the hydrogen atom from the first Bohr orbit to the fifth Bohr orbit and what is the wavelength of the light emitted when the electron returns to the ground state? The ground state electron energy is –2.18 × 10^–11 ergs.

Explain, giving reasons, which of the following sets of quantum numbers are not possible.

1. n = 0, l = 0, ml = 0, ms = + ½
2. n = 1, l = 0, ml = 0, ms = – ½
3. n = 1, l = 1, ml = 0, ms = + ½
4. n = 2, l = 1, ml = 0, ms = – ½
5. n = 3, l = 3, ml = –3, ms = + ½
6. n = 3, l = 1, ml = 0, ms = + ½

How many electrons in an atom may have the following quantum numbers?

n = 4, `m_s =  -1/2`

How many electrons in an atom may have the following quantum numbers?

n = 3, l = 0

Show that the circumference of the Bohr orbit for the hydrogen atom is an integral multiple of the de Broglie wavelength associated with the electron revolving around the orbit.