Download App

Model Paper 5 — Chemistry STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceChemistryModel Paper 51 Mark
MCQ
Assertion (A): Overlapping in benzene is $sp ^2- sp ^2$ type.
Reason (R): C-C bond length in benzene is $1.3 \stackrel{\circ}{A}$.
  • A
    Both A and R are true and R is the correct explanation of A.
  • B
    Both A and R are true but R is not the correct explanation of A.
  • ✓
    A is true but R is false.
  • D
    Both A and R are false.
✓

Answer

Correct option: C.
A is true but R is false.
(c) A is true but R is false.
Explanation: C-C bond length in benzene is $1.39 \stackrel{o}{A}$ which is greater than C=C bond length of $1.34 \stackrel{o}{A}$ and less than C-C bond length of $1.54 \stackrel{\circ}{A}$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Assertion (A) & Reason (B) MCQ" from Model Paper 5→Model Paper 5 — all question types→Chemistry STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Assertion (A): In the dissociation of $PCl _5$ at constantp ressure and temperature, addition of helium at equilibrium increases the dissociation of $PCl _5$.
Reason (R): Helium reacts with $Cl _2$ and hence shifts the equilibrium in forward direction.
→
Direction in the following Questions, the Assertion and Reason have been put forward. Read the statements carefully and choose the correct alternative from the following :
Assertion : The molecular orbitals with higher energy is called anti bonding orbitals.
Reason : The anti bonding nature of a molecular orbital is indicated by an asterisk over its designation.
→
In the following Questions, the Assertion and Reason hrve been put forfiird. Read the statements csrefully end choose the correct alternative from the following:
Assertion : A Mixture of $o-$ nitrophenol and $p-$ nitrophenol can be separated by steam distillation.
Reason : $p-$ nitrophenol is steam volatile while $o-$ nitrophenol is not steam volatile.
→
Notes : In the following questions a statement of Assertion $(A)$ followed by a statement of Reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : A liquid crystallises into a solid and is accompanied by decrease in entropy.
Reason $(R)$ : In crystals, molecules organise in an ordered manner.
→
Note : In the following questions a statement of Assertion $(A)$ followed by a statement of Reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : One atomic mass unit is defined as one twelfth of the mass of one carbon $-12$ atom.
Reason $(R)$ : Carbon $-12$ isotope is the most abundunt isotope of carbon and has been chosen as standard.
→
Note : In the following questions a statement of assertion $(A)$ followed by a statement of reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : Redox couple is the combination of oxidised and reduced form of a substance involved in an oxidation or reduction half cell.
Reason $(R)$ : In the representation $\text{E}^\ominus_{\text{Fe}^{3+}/\text{Fe}^{2+}}$ and $\text{E}^\ominus_{\text{Cu}^{2+}/\text{Cu}},\text{Fe}^{3+}/\text{Fe}^{2+}$ and $\text{Cu}^{2+}/\text{Cu}$ are redox couples.
→
Note : In the following questions a statement of Assertion $(A)$ followed by a statement of Reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : Combustion of $16g$ of methane gives $18g$ of water.
Reason $(R)$ : In the combustion of methane, water is one of the products.
→
In the following questions a statement of assertion $(A)$ followed by a statement of reason $(R)$ is given. Choose the correct option out of the choices given below each question.
Assertion $(A)$ : Toluene on Friedal Crafts methylation gives $o–$ and $p–$ xylene.
Reason $(R)$ : $\text{CH}_3-$ group bonded to benzene ring increases electron density at $o–$ and $p–$ position.
→
Assertion (A): In Sommerfeld's model, circular orbit is possible for the electron in K shell.
Reason (R): Electron present in $K$ shell corresponds to principal quantum number $n =1$.
→
Assertion $(A)$ : The temperature at which vapour pressure of a liquid is equal to the external pressure is called boiling temperature.
Reason $(R)$ : At high altitude atmospheric pressure is high.
→