National Standard Examination in Chemistry (NSEC) Solved Paper 2016 Part-4

Download PDF of This Page (Size: 138K)

Q: 13. Which one of the following information about the compounds is correct?

Q_13_Find the Correct Compounds in a Table
Q_13_Find the Correct Compounds in a Table

Compounds

Oxidation state of P

No. of P-OH bonds

No. of P-H bonds

No. of P=O bonds

[I] Hypophosphorous acid

1+

2

1

0

[II] Pyropophosphorous acid

3+

2

2

2

[III] Hypophosphoric acid

4+

2

2

2

[IV] Pyrophosphoric acid

5+

3

1

4

(A) I

(B) III

(C) IV

(D) II

Answer: (D)

Q: 14. The best method of preparation of 2-benzyloxynaphthalene is a base catalysed reaction of:

(A) Benzyl chloride and 1-naphthol

(B) 1-chloromethylnapthalene and phenol

(C) 1-Chaloronaphtalene and benzyl alcohol

(D) Benzyl alcohol and 1-naphthol

Answer: N/A

Q: 15. The pair that is isostructural (i.e. having the same shape and hybridization) is

(A)

(B)

(C)

(D)

Answer: (B)

Q: 16. A group, which departs from the substrate in a nucleophilic substitution reaction is called a leaving group. The ease of departure is determined by the acidity of the conjugate acid of the leaving group; higher the acidity better is the leaving group. The correct order of the reactivity of the following compounds in a given nucleophilic reaction is:

(A)

(B)

(C)

(D)

Answer: (D)

Q: 17. If a dilute solution of aqueous is saturated with then the product formed is:

(A)

(B)

(C)

(D)

Answer: (B)

For detailed explanations and answers visit - NSEC Answers with detailed explanations

No more confusion, prepare with fully solved previous years questions and detailed FREE video lessons for all Olympiads: NSO, NCO, IMO, and IEO for all classes.