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

Assertion (A): Pent- 1- ene and pent- 2- ene are position isomers.

Reason (R): Position isomers differ in the position of functional group or a substituent.

The molecules having dipole moment are:

(i) 2,2-Dimethylpropane

(ii) trans-Pent-2-ene

(iii) cis-Hex-3-ene

(iv) 2, 2, 3, 3 - Tetramethylbutane.

Assertion (A): The compound cyclooctane has the following structural formula:

It is cyclic and has conjugated 8π-electron system but it is not an aromatic compound.

Reason (R): (4n + 2)π electrons rule does not hold good and ring is not planar.

During an educational trip, a student of botany saw a beautiful lake in a village. She collected many plants from that area. She noticed that villagers were washing clothes around the lake and at some places waste material from houses was destroying its beauty. After few years, she visited the same lake again. She was surprised to find that the lake was covered with algae, stinking smell was coming out and its water had become unusable. Can you explain the reason for this condition of the lake?

What are the major differences between metals and non-metals?

Considering the elements B, Al, Mg, and K, the correct order of their metallic character is ______.

Considering the elements B, C, N, F, and Si, the correct order of their non-metallic character is:

A student forgot to add the reaction mixture to the round-bottomed flask at 27 °C but instead, he/she placed the flask on the flame. After a lapse of time, he realized his mistake and using a pyrometer he found the temperature of the flask was 477 °C. What fraction of air would have been expelled out?

In terms of Charles’ law explain why - 273°C is the lowest possible temperature.

Find out the value of K_c for each of the following equilibria from the value of K_p:

\[\ce{2NOCl (g) ⇌ 2NO (g) + Cl2 (g)}\]; K_p= 1.8 × 10^-2 at 500 K

Find out the value of K_c for each of the following equilibria from the value of K_p:

\[\ce{CaCO3 (s) ⇌ CaO(s) + CO2(g)}\]; K_p= 167 at 1073 K

A sample of HI(g) is placed in flask at a pressure of 0.2 atm. At equilibrium, the partial pressure of HI(g) is 0.04 atm. What is Kp for the given equilibrium?

\[\ce{2HI (g) ⇌ H2 (g) + I2 (g)}\]

How will green chemistry help decrease environmental pollution?

Write IUPAC name of the following compound:

CH₃CH = C(CH₃)₂

In the alkane H₃C–CH₂–C(CH₃)₂–CH₂–CH(CH₃)₂, identify 1°,2°,3° carbon atoms and give the number of H atoms bonded to each one of these.

A sample of pure PCl₅ was introduced into an evacuated vessel at 473 K. After equilibrium was attained, the concentration of PCl₅ was found to be 0.5 × 10^–1 mol L^–1. If the value of K_c is 8.3 × 10^–3, what are the concentrations of PCl₃ and Cl₂ at equilibrium?

\[\ce{PCl5 (g) ⇌ PCl3 (g) + Cl2(g)}\]

At 1127 K and 1 atm pressure, a gaseous mixture of CO and CO₂ in equilibrium with solid carbon has 90.55% CO by mass

\[\ce{C (s) + CO2 (g) ⇌ 2CO (g)}\]

Calculate K_c for this reaction at the above temperature.

For the following bond cleavages, use curved arrows to show the electron flow and classify homolysis or heterolysis. Identify reactive intermediate produced as free radical, carbocation and carbanion.

\[\ce{CH3O - OCH3 -> CH3\overset\bullet{\text{O}} + \overset\bullet{\text{O}}CH3}\]

For the following bond cleavages, use curved-arrows to show the electron flow and classify as homolysis or heterolysis. Identify reactive intermediate produced as free radical, carbocation and carbanion.