You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Chemistry

Types of Redox Reactions

Assertion :Co...

Question

Assertion :Conc. $H_{2} S O_{4}$ can not be used to prepare pure HBr from NaBr. Reason: It reacts slowly with NaBr

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Assertion is correct but Reason is incorrect

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Both Assertion and Reason are incorrect

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C Assertion is correct but Reason is incorrect
HBr cannot be prepared by the action of conc. $H_{2} S O_{4}$ on NaBr because $H_{2} S O_{4}$ is an oxidising agent and $H B r$ is strong reducing agent. $HBr$ reduces sulphuric acid to sulphur dioxide and itself is oxidised to bromine. Hence, HBr is prepared by heating NaBr with conc. phosphoric acid. Same is true for the preparation of HI. Thus, assertion is correct but reason is incorrect.
$N a B r + H_{2} S O_{4} \to N a H S O_{4} + H B r H_{2} S O_{4} + 2 H B r \to S O_{2} + B r_{2} + 2 H_{2} O$

Suggest Corrections

Similar questions

Q. Assertion: The compressibility factor for

H_{2}

and

H e

(1 + \frac{P b}{R T})

Reason: The compressibility factor for

H_{2}

and

H e

can be derived from Van der Waal's equation.

Assertion – The non-fusible impurities present in iron ore are removed by $C a C O_{3}$ .

Reason: $C a C O_{3}$ which decomposes into $C a O$ and $C O_{2}$ . The $C a O$ formed reacts with $S i O_{2}$ to remove silica

Q. Assertion: The impurities such as

{SiO}_{2}

present in iron ore is removed by

{CaCO}_{3}

.

Reason:

CaO

formed by decomposition of

{CaCO}_{3}

reacts with

{SiO}_{2}

to form slag.

Assertion (A) Phenols give o-and p-nitrophenol on nitration with conc. $H N O_{3} a n d H_{2} S O_{4}$ mixture.
Reason (R) - OH group in phenol is o-,p-directing.
(a) Assertion and reason both are correct and reason is correct explanation of assertion.
(b) Assertion and reason both are wrong statements.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
(e) Both assertion and reason are correct statements but reason is not correct explanation of assertion.

Assertion (A) Order of the reaction can be zero or fractional.

Reason (R) We cannot determine order from balanced chemical equation.

(a) Both assertion and reason are correct and the reason is correct explanation of assertion
(b) Both assertion and reason are correct, but reason does not explain assertion.
(c) Assertion is correct, but reason is incorrect
(d) Both assertion and reason are incorrect
(e) Assertion is incorrect but reason is correct.

Join BYJU'S Learning Program

Assertion :Conc. H2SO4 can not be used to prepare pure HBr from NaBr. Reason: It reacts slowly with NaBr

Assertion :Conc. $H_{2} S O_{4}$ can not be used to prepare pure HBr from NaBr. Reason: It reacts slowly with NaBr