Thursday, May 16, 2013

Presence of halogen in organic compounds can be detected using Beilstien's test


271.    Presence of halogen in organic compounds can be detected using
(A) Beilstien's test
(B) kjeldahl test
(C) Duma's test
(D) Leibig's test
Answer:: (A)

272.    Rate of physical adsorption increases with
(A) decrease in pressure
(B) increase in temperature
(C) decrease in surface area
(D) decrease in temperature
Answer:: (D)

273.    Reaction of methyl bromide with aqueous sodium hydroxide involves ______.
(A) SN 1 mechanism
(B) racemisation
(C) SN2 mechanism
(D) inversion of configuration
Answer:: (C)

274.    Standard electrode potential for Sn4+ / Sn2+ couple is +0.15 V and that for the Cr3+ / Cr couple is –0.74 V. These two couples in their standard state are connected to make a cell. The cell potential will be
(A) +1.83 V
(B) +1.19 V
(C) +0.89 V
(D) +0.18 V
Answer:: (C)
275.    Standard electrode potential of three metals X, Y and Z are –1.2 V, +0.5 V and –3.0 V respectively. The reducing power of these metals will be
(A) X > Y > Z
(B) Y > Z > X
(C) Y > X > Z
(D) Z > X > Y
Answer:: (D)

276.    The activation energy for a reaction at the temperature TK was found to be 2.303 RT J mol-1. The ratio of the rate constant to Arrhenius factor is ______.
(A) 10-2
(B) 10-1
(C) 2´10-2
(D) 2´10-3
Answer:: (B)

277.    The amino acid which is not optically active is
(A) glycine
(B) alanine
(C) serine
(D) lactic acid
Answer:: (A)

278.    The amount of heat evolved when 500 cm3 of 0.1 M HCI is mixed with 200 cm3 of 0.2 M NaOH is ______.
(A) 1.292 kJ
(B) 2.292 kJ
(C) 3.392 kJ
(D) 0.292 kJ
Answer:: (B)

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