Sunday, June 29, 2008

Aldehydes - 9 - (Aromatic)

A mixture of benzaldehyde and formaldehyde on heating with acqueous NaOH solution gives

a. benzyl alcohol and sodium formate
b. sodium benzoate and methyl alcohol
c. sodium benzoate and sodium formate
d. benzyl alcohol and methyl alcohol

(JEE 2001)

Answer: (a)

Because formadehyde gets converted formic acid

Sunday, June 22, 2008

Carbohydrates - 10 - Tests

1. The pair of compounds showing positive Tollens reagent test is

a. glucose and sucrose
b. fructose and sucrose
c. glucose and fructose
d. acetephenone and pentanal

(JEE 2004)

Answer: c

Reducing sugars show this test. Both glucose and fructose are reducing sugars.

Polymers - 6

1. Match the chemical substances in Column I with type of polymers/type of bonds in Column II.

(JEE 2007)

Column I ..........Column II
(A) cellulose............ (p) natural polymer
(B) nylon-6, 6 ............(q) synthetic polymer
(C) protein ...............(r) amide linkage
(D) sucrose................ (s) glycoside linkage


Answer (A) p, s (B) q, r (C) p, r (D) s