IIT-JEE-Chemistry-Final Revision Set No.83

1. The percentage of p-character in the orbitals forming P-P bonds in P4 is

(A) 25 (B) 33

(C) 50 (D) 75

2. When 20g of naphthoic acid (C11H8O2) is dissolved in 50 g of benzene (Kf = 1.72 K kg mol-1), a freezing point depression of 2K is observed. The van't Hoff factor (i) is---?

3. STATEMENT-1

Boron always forms covalent bond

Because

STATEMENT-2

The small size of B3+ favours formation of covalent bond.

(A) Statement-1 is True, Staement-2 is True, Statement-2 is a correct explanation for statement-1.

(B) Statement-1 is True, Staement-2 is True, Statement-2 is not a correct explanation for statement-1.

(C) Statement-1 is True, Statement-2 is False

(D) Statement-1 is False, Statement-2 is True

4. STATEMENT-1

In water, orthoboric acid behaves as a weak monobasic acid.

Because

STATEMENT-2

In water, orthoboric acid acts as a proton donor.

(A) Statement-1 is True, Staement-2 is True, Statement-2 is a correct explanation for statement-1.

(B) Statement-1 is True, Staement-2 is True, Statement-2 is not a correct explanation for statement-1.

(C) Statement-1 is True, Statement-2 is False

(D) Statement-1 is False, Statement-2 is True

5. Argon is used in arc welding because of its

(A) low reactivity with metal

(B) ability to lower the melting point of metal

(C) flammability

(D) high calorific value


Source: JEE 2007 paper 1