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WBJEE 2015 Solved Chemistry Question Paper Part 6

Mar 6, 2017 17:56 IST

    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)

    Sol:

    We have,

     pH = 5.74,

    pKa = 4.74,

    Let the volume of acid solution = x L,

    Also, Volume of salt solution = y L

    We have,

    WBJEE 2015, Chemistry Paper

    WBJEE 2016 Solved Physics and Chemistry Question Paper

    67. The reaction of methyltrichloroacetate (Cl3CCO2Me) with sodium methoxide (NaOMe) generates

    (A) Carbocation

    (B) Cabene

    (C) Carbanion

    (D) Carbon radical

    Ans : (B)

    Sol:

    WBJEE 2015, Chemistry Paper

    68. Best reagent for nuclear iodination of aromatic compounds is

    (A) KI/CH3COCH3

    (B) I2/CH3CN

    (C) KI/CH3COOH

    (D) I2/HNO3

    Ans : (D)

    Sol:

    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)

    Sol:

    Lassaigne’s test is conducted to detect the halogens, nitrogen and sulphur in an organic compound.

    WBJEE 2015, Chemistry Paper

    So, the appearance of blue coloured compound is due to ferric ferrocyanide.

    70. In the following reaction

    WBJEE 2015, Chemistry Paper

    The product ‘P’ is

    (A) RCHO

    (B) R2CHOEt

    (C) R3CH

    (D) RCH(OEt)2

    Ans : (A)

    Sol:

    The reaction can be written as:

    WBJEE 2015, Chemistry Paper

    Also Get:

    WBJEE Sample Papers

    WBJEE Previous Years' Question Papers

    WBJEE Online Test

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