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

Assertion (A): Components of a mixture of red and blue inks can be separated by distributing the components between stationary and mobile phases in paper chromatography.

Reason (R): The coloured components of inks migrate at different rates because paper selectively retains different components according to the difference in their partition between the two phases.

You have a mixture of three liquids A, B and C. There is a large difference in the boiling points of A and rest of the two liquids i.e., B and C. Boiling point of liquids B and C are quite close. Liquid A boils at a higher temperature than B and C and boiling point of B is lower than C. How will you separate the components of the mixture. Draw a diagram showing set up of the apparatus for the process.

A liquid with high boiling point decomposes on simple distillation but it can be steam distilled for its purification. Explain how is it possible?

Despite their - I effect, halogens are o- and p-directing in haloarenes. Explain.

Suggest a route to prepare ethyl hydrogensulphate (CH₃ – CH₂ – OSO₂ – OH) starting from ethanol (C₂H₅OH).

An alkene ‘A’ contains three C – C, eight C – H σ bonds and one C – C π bond. ‘A’ on ozonolysis gives two moles of an aldehyde of molar mass 44 u. Write IUPAC name of ‘A’.

Calcium carbonate reacts with aqueous HCl to give CaCl₂ and CO₂ according to the reaction,

\[\ce{CaCO_{3(s)} + 2 HCl_{(aq)} → CaCl_{2(aq)} + CO_{2(g)} + H2O_{(l)}}\]

What mass of CaCO₃ is required to react completely with 25 mL of 0.75 M HCl?

Chlorine is prepared in the laboratory by treating manganese dioxide (MnO₂) with aqueous hydrochloric acid according to the reaction

\[\ce{4HCl_{(aq)} + MnO_{2(s)} → 2H2O_{(l)} + MnCl_{2(aq)} + Cl_{2(g)}}\]

How many grams of HCl react with 5.0 g of manganese dioxide?

Symbols `""_35^79"Br"` and `""^79"Br"` can be written, whereas symbols `""_79^35"Br"` and `""^35"Br"` are not acceptable. Answer briefly.

The quantum numbers of six electrons are given below. Arrange them in order of increasing energies. If any of these combination(s) has/have the same energy lists:

1. n = 4, l = 2, m_l = –2 , m_s = - 1/2
2. n = 3, l = 2, m_l= 1 , m_s = +1/2
3. n = 4, l = 1, m_l = 0 , m_s = +1/2
4. n = 3, l = 2, m_l = –2 , m_s = –1/2
5. n = 3, l = 1, m_l = –1 , m_s= +1/2
6. n = 4, l = 1, m_l = 0 , m_s = +1/2

How many sub-shells are associated with n = 4?

How many electrons will be present in the sub-shells having m_s value of - 1/2 for n = 4?

Explain the physical significance of Van der Waals parameters.

Knowing the properties of H₂O and D₂O, do you think that D₂O can be used for drinking purposes?

What is \[\ce{SI}\] unit of viscosity coefficient (η)?

Write redox reaction between fluorine and water.

Correlate the items listed in Column I with those listed in Column II. Find out as many correlations as you can.

Match the terms in Column I with the relevant item in Column II.

In a reaction, \[\ce{A + B2 -> AB2}\]

Identify the limiting reagent, if any, in the following reaction mixture.

300 atoms of A + 200 molecules of B

In a reaction, \[\ce{A + B2 -> AB2}\]

Identify the limiting reagent, if any, in the following reaction mixture.

2 mol A + 3 mol B