JEE Main 2021 Question Paper (26-Aug-2021) (Shift 2)

Question 1

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Barium carbonate is insoluble in water and is highly stable.
Reason (R): The thermal stability of the carbonates increases with increasing cationic size.
Choose the most appropriate answer from the options given below :

Accepted Answer

Both (A) and (R) are true.

Answer

(A) is true but (R) is false.

Answer

(A) is false but (R) is true.

Answer

Both (A) and (R) are false.

Question 2

The major product in the above reaction is:

Accepted Answer

""

Answer

Answer

Answer

Question 3

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Sucrose is a disaccharide and a non-reducing sugar.
Reason (R): Sucrose involves glycosidic linkage between $C_{1}$ of $\beta$-glucose and $C_{2}$ of $\alpha$-fructose.
Choose the most appropriate answer from the options given below :

Accepted Answer

(A) is true but (R) is false.

Answer

Both (A) and (R) are true and (R) is the true explanation of (A).

Answer

(A) is false but (R) is true.

Answer

Both (A) and (R) are true but (R) is not the true explanation of (A).

Question 4

Match List - I with List - II. List - I (Chemical Reaction) List - II (Reagent used) a $ \mathrm{CH}_3\mathrm{COOCH}_2\mathrm{CH}_3 	o \mathrm{CH}_3\mathrm{COOH} + \mathrm{CH}_3\mathrm{CH}_2\mathrm{OH} $ i $ \mathrm{CH}_3\mathrm{MgBr} / \mathrm{H}_3\mathrm{O}^+ \quad 	ext{(one equivalent)} $ b $ \mathrm{CH}_3\mathrm{COOCH}_3 	o \mathrm{CH}_3\mathrm{CHO} $ ii $ \mathrm{H}_2\mathrm{SO}_4 / \mathrm{H}_2\mathrm{O} $ c $ \mathrm{CH}_3\mathrm{C} \equiv \mathrm{N} 	o \mathrm{CH}_3\mathrm{CHO} $ iii $ \mathrm{DIBAL}-\mathrm{H} / \mathrm{H}_2\mathrm{O} $ d iv $ \mathrm{SnCl}_2, \mathrm{HCl} / \mathrm{H}_2\mathrm{O} $ Choose the most appropriate match.

Accepted Answer

$(\mathrm{a}) - (\mathrm{ii}), \quad (\mathrm{b}) - (\mathrm{iii}), \quad (\mathrm{c}) - (\mathrm{iv}), \quad (\mathrm{d}) - (\mathrm{i})$

Answer

$(\mathrm{a}) - (\mathrm{ii}), \quad (\mathrm{b}) - (\mathrm{iv}), \quad (\mathrm{c}) - (\mathrm{iii}), \quad (\mathrm{d}) - (\mathrm{i})$

Answer

$(\mathrm{a}) - (\mathrm{iii}), \quad (\mathrm{b}) - (\mathrm{ii}), \quad (\mathrm{c}) - (\mathrm{i}), \quad (\mathrm{d}) - (\mathrm{iv})$

Answer

$(\mathrm{a}) - (\mathrm{iv}), \quad (\mathrm{b}) - (\mathrm{ii}), \quad (\mathrm{c}) - (\mathrm{iii}), \quad (\mathrm{d}) - (\mathrm{i})$

Question 5

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Heavy water is used for the study of reaction mechanism.
Reason (R): The rate of reaction for the cleavage of $ \mathrm{O}-\mathrm{H}$ bond is slower than that of $ \mathrm{O}-\mathrm{D}$ bond.
Choose the most appropriate answer from the options given below :

Accepted Answer

$ \left(\mathrm{A}\right)$ is true but $ \left(\mathrm{R}\right)$ is false.

Answer

Both $ \left(\mathrm{A}\right)$ and $ \left(\mathrm{R}\right)$ are true and $ \left(\mathrm{R}\right)$ is the true explanation of $ \left(\mathrm{A}\right)$.

Answer

$ \left(\mathrm{A}\right)$ is false but $ \left(\mathrm{R}\right)$ is true.

Answer

Both $ \left(\mathrm{A}\right)$ and $ \left(\mathrm{R}\right)$ are true but $ \left(\mathrm{R}\right)$ is not the true explanation of $ \left(\mathrm{A}\right).$

	List - I (Chemical Reaction)		List - II (Reagent used)
a	\[ \mathrm{CH}_3\mathrm{COOCH}_2\mathrm{CH}_3 \to \mathrm{CH}_3\mathrm{COOH} + \mathrm{CH}_3\mathrm{CH}_2\mathrm{OH} \]	i	\[ \mathrm{CH}_3\mathrm{MgBr} / \mathrm{H}_3\mathrm{O}^+ \quad \text{(one equivalent)} \]
b	\[ \mathrm{CH}_3\mathrm{COOCH}_3 \to \mathrm{CH}_3\mathrm{CHO} \]	ii	\[ \mathrm{H}_2\mathrm{SO}_4 / \mathrm{H}_2\mathrm{O} \]
c	\[ \mathrm{CH}_3\mathrm{C} \equiv \mathrm{N} \to \mathrm{CH}_3\mathrm{CHO} \]	iii	\[ \mathrm{DIBAL}-\mathrm{H} / \mathrm{H}_2\mathrm{O} \]
d		iv	\[ \mathrm{SnCl}_2, \mathrm{HCl} / \mathrm{H}_2\mathrm{O} \]