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

Which of the following ions is more stable? Use resonance to explain your answer.

The structure of triphenylmethyl cation is given below. This is very stable and some of its salts can be stored for months. Explain the cause of high stability of this cation.

Draw the resonance structure of the following compounds;

Draw the resonance structure of the following compounds;

CH₂ = CH – CH = CH₂

Draw the resonance structure of the following compounds;

\[\begin{array}{cc}
\ce{CH2 = CH - C = O}\\
\phantom{.........}|\\
\phantom{.........}\ce{H}
\end{array}\]

Which of the following compounds will not exist as resonance hybrid. Give reason for your answer:

Resonance structures of propenal are given below. Which of these resonating structures is more stable? Give reason for your answer.

\[\ce{\underset{I}{CH2 = CH - CH = O} <-> \underset{II}{\overset{⊕}{C}H2 - CH = CH - \overset{Θ}{O}}}\]

Which of the two structures (A) and (B) given below is more stabilised by resonance? Explain.

\[\ce{\underset{(A)}{CH3COOH}}\] and \[\ce{\underset{(B)}{CH3CO\overset{Θ}{O}}}\] 

Assertion (A): Energy of resonance hybrid is equal to the average of energies of all canonical forms.

Reason (R): Resonance hybrid cannot be presented by a single structure.

Calculate the atomic mass (average) of chlorine using the following data :-

Why do elements in the same group have similar physical and chemical properties?

Predict the formula of the stable binary compounds that would be formed by the combination of the following pair of elements.

Lithium and oxygen

Predict the formula of the stable binary compounds that would be formed by the combination of the following pair of elements.

Magnesium and nitrogen

Predict the formula of the stable binary compounds that would be formed by the combination of the following pair of elements.

Aluminium and iodine

Predict the formula of the stable binary compounds that would be formed by the combination of the following pair of elements.

Silicon and oxygen

Predict the formula of the stable binary compounds that would be formed by the combination of the following pair of elements.

Element 71 and fluorine

Predict the formula of the stable binary compounds that would be formed by the combination of the following pair of elements.

Phosphorus and fluorine

Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?

What is the wavelength of light emitted when the electron in a hydrogen atom undergoes a transition from an energy level with n = 4 to an energy level with n = 2?

Calculate the wave number for the longest wavelength transition in the Balmer series of atomic hydrogen.