Science (English Medium) कक्षा ११ - CBSE Question Bank Solutions for Chemistry

\[\ce{BF3}\] does not have proton but still acts as an acid and reacts with \[\ce{NH3}\]. Why is it so? What type of bond is formed between the two?

A reaction between ammonia and boron trifluoride is given below: \[\ce{NH3 + BF3 -> H3N : BF3}\] Identify the acid and base in this reaction. Which theory explains it? What is the hybridisation of B and N in the reactants?

Match the following species with the corresponding conjugate acid:

Match the type of mixture of compounds in Column I with the technique of separation/purification given in Column II.

Assertion (A): Simple distillation can help in separating a mixture of propan-1-ol (boiling point 97°C) and propanone (boiling point 56°C).

Reason (R): Liquids with a difference of more than 20°C in their boiling points can be separated by simple distillation.

Two liquids (A) and (B) can be separated by the method of fractional distillation. The boiling point of liquid (A) is less than boiling point of liquid (B). Which of the liquids do you expect to come out first in the distillate? Explain.

Draw a diagram of bubble plate type fractionating column. When do we require such type of a column for separating two liquids. Explain the principle involved in the separation of components of a mixture of liquids by using fractionating column. What industrial applications does this process have?

Arrange the following carbanions in order of their decreasing stability.

(A) H₃C – C ≡ C^–

(B) H – C ≡ C^–

(C) \[\ce{H3C - C\overset{-}{H2}}\]

Which of the following are correct?

(i) \[\ce{CH3 - O - CH^{⊕}2}\] is more stable than \[\ce{CH3 - CH^{⊕}2}\]

(ii) (CH₃)₂CH^⊕ is less stable than \[\ce{CH3 - CH2 - CH^{⊕}2}\]

(iii) \[\ce{CH3 = CH2 - CH^{⊕}2}\] is more stable than \[\ce{CH3 - CH2 - CH^{⊕}2}\]

(iv) \[\ce{CH2 - CH^{⊕}}\] is more stable than \[\ce{CH3 - CH^{⊕}2}\]

How will you convert benzene into p – nitrobromobenzene

How will you convert benzene into m – nitrobromobenzene

Arrange the following set of compounds in the order of their decreasing relative reactivity with an electrophile. Give reason.

The relative reactivity of 1°, 2°, 3° hydrogen’s towards chlorination is 1 : 3.8 : 5. Calculate the percentages of all monochlorinated products obtained from 2-methylbutane.

The bromine atom possesses 35 electrons. It contains 6 electrons in 2p orbital, 6 electrons in 3p orbital and 5 electrons in 4p orbital. Which of these electron experiences the lowest effective nuclear charge?

Among the following pairs of orbitals which orbital will experience the larger effective nuclear charge?

1. 2s and 3s,
2. 4d and 4f,
3. 3d and 3p

Write the significance of a plus and a minus sign shown in representing the orbitals.

A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be ______.

For the reaction, \[\ce{2Cl_{(g)} → Cl_{2(g)}}\], what are the signs of ΔH and ΔS?

What are the necessary conditions for any system to be aromatic?

Explain why the following system is not aromatic?