Find WBJEE 2015 Solved Chemistry Question Paper – Part 6 in this article. This paper consists of 5 questions (#66 to #70) from WBJEE 2015 Chemistry paper. Detailed solution of these questions has been provided so that students can match their solutions.
Importance of Previous Years’ Paper:
Previous years’ question papers help aspirants in understanding exam pattern, question format, important topics and assessing preparation. It has also been seen that sometimes questions are repeated in WBJEE Exam. So, this paper will certainly boost your confidence.
About WBJEE Exam
WBJEE is a common entrance examinations held at state level for admission to the Undergraduate Level Engineering and Medical courses in the State of West Bengal. The Chemistry section of WBJEE 2015 engineering entrance exam consists of 40 questions.
66. The ratio of volumes of CH3COOH 0.1 (N) to CH3COONa 0.1 (N) required to prepare a buffer solution of pH 5.74 is (given : pKa of CH3COOH is 4.74)
(A) 10 : 1
(B) 5 : 1
(C) 1 : 5
(D) 1 : 10
Ans : (D)
pH = 5.74,
pKa = 4.74,
Let the volume of acid solution = x L,
Also, Volume of salt solution = y L
67. The reaction of methyltrichloroacetate (Cl3CCO2Me) with sodium methoxide (NaOMe) generates
(D) Carbon radical
Ans : (B)
68. Best reagent for nuclear iodination of aromatic compounds is
Ans : (D)
The best reagent for the iodination of aromatic compound is I2/HNO3
69. In the Lassaigne’s test for the detection of nitrogen in an organic compound, the appearance of blue coloured compound is due to
(A) ferric ferricyanide
(B) ferrous ferricyanide
(C) ferric ferrocyanide
(D) ferrous ferrocyanide
Ans : (C)
Lassaigne’s test is conducted to detect the halogens, nitrogen and sulphur in an organic compound.
So, the appearance of blue coloured compound is due to ferric ferrocyanide.
70. In the following reaction
The product ‘P’ is
Ans : (A)
The reaction can be written as: