Download App

p-Block Elements – I — Chemistry STD 12 — Question

Tamilnadu BoardEnglish MediumSTD 12Chemistryp-Block Elements – I1 Mark
MCQ
Assertion $( A )- BF _3$ reacts with ammonia to form complex.
Reason $(R) - BF _3$ is a electron deficient compound and accepts electron pairs to form coordinate covalent bonds.
  • ✓
    A and R are correct and R explains A.
  • B
    A and R are correct and R not explains A.
  • C
    A is correct but R is wrong.
  • D
    A is wrong but R is correct.
✓

Answer

Correct option: A.
A and R are correct and R explains A.
A and R are correct and R explains 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 And Reason." from p-Block Elements – I→p-Block Elements – I — all question types→Chemistry STD 12 question papers→Tamilnadu Board STD 12 question papers→Tamilnadu Board question paper generator→

Similar questions

Assertion(A) - Aluminium can be used as a reducing agent for the reduction of chromic oxide.
Reason $(R)$ - In the Ellingham diagram, formation of chromium oxide lies above that of the aluminium, therefore $Al _2 O _3$ is more stable than $Cr _2 O _3$.
(a) A and R are correct, R explains A
(b) A and R are correct, R does not explains A
(c) $A$ is correct but $R$ is wrong
(d) A is wrong but R is correct
→
Assertion(A) – Aluminium is used in the j design of chemical reactors.
Reason (R) – Aluminium has high resistance to corrosion.
(a) A and R are correct, R explains A
(b) A and R are correct, R does not explains A
(c) A is correct but R is wrong
(d) A is wrong but R is correct
→
 (A): Powdered calcium carbonate reacts much faster with dilute
HCL than with the same mass of $CaCO _3$ as marble.
Reason (R): For a given mass of a reactant, when the particle size decreases, surface area increases. Increase in surface area of the reactant leads to more collisions per litre per second and hence the rate of the reaction also increases.
(a) Both $A$ and $R$ are correct and $R$ is the correct explanation of $A$.
(b) Both $A$ and $R$ arc correct but $R$ is not correct explanation of $A$
(c) A is correct but $R$ is wrong
(d) A is wrong but R is correct
→
Assertion (A) – Diborane is highly reactive.
Reason (R) – At high temperatures, diborane forms higher boranes.
→
Assertion(A): With the increase in temperature, the ionic product of water also increases.
Reason (R): The dissociation of water is an endothermic reaction.
(a) Both A and R are correct and R is the correct explanation of A
(b) A is correct but R is wrong
(c) A is wrong but R is correct
(d) Both A and R are wrong
→
(A): Order of the reaction can be zero or fractional
Reason (R): We cannot determine order from balanced chemical equation
(a) Both A and R are correct but R is not correct explanation of A.
(b) Both A and R are correct and R is the correct explanation of A
(c) A is correct but R is wrong
(d) A is wrong but R is correct
→
Assertion (A) – Nitrogen gas is chemically inert.
Reason (R) – Nitrogen has low bonding energy.
→
(A): Alcohols cannot be used as solvent for Grignard reagent.
Reason (R): Alcohols are decomposed by Grignard reagents to give alkane.
(a) Both A and R are correct and R is the correct explanation of A.
(b) A is correct but R is wrong
(c) A is wrong but R is correct
(d) Both A and R are correct but R is not correct explanation of A.
→
$(A): LiAlH _4$ is the best reagent to prepare unsaturated alcohols from carbonyl compounds.
Reason (R): $LiAlH _4$ does not reduce the carbon - carbon double bond present in the carbonyl carbon compound.
(a) Both A and R are correct and R is the correct explanation of A .
(b) Both $A$ and $R$ are correct but $R$ is not the correct explanation of $A$.
(c) $A$ is correct but $R$ is wrong
(d) A is wrong but R is correct
→
(A): Both alcohol and ether have higher boiling point.
Reason (R): Both are having intermolecular hydrogen bonding.
(a) Both A and R are correct and R is the correct explanation of A.
(b) Both A and R are wrong
(c) A is correct but R is wrong
(d) A is wrong but R is correct
→