Hydrogen gas is not liberated when the following metal is added to dil. HCl

219.    Hydrogen gas is not liberated when the following metal is added to dil. HCl

(A) Ag

(B) Zn

(C) Mg

(D) Sn

Answer:: (A)

220.    Hydroxyl ion concentration of 1M HCl is

(A) 1 ´ 1014mol dm-3

(B) 1 ´ 10-1mol dm-3

(C) 1 ´ 10-13mol dm-3

(D) 1 ´ 101mol dm-3

Answer:: (A)

221.    Identify the ore not containing iron

(A) chalcopyrites

(B) carnallite

(C) siderite

(D) limonite

Answer:: (B)

222.    Identify the reaction that does not take place in a blast furnace.

(A) CaCO3 ¾® CaO + CO2

(B) CaO + Si O2 ¾® Ca Si O2 ¾® Ca Si O3

(C) 2Fe2O3 + 3C ¾® 4Fe + 3CO2

(D) CO2 + C ¾® 2CO

Answer:: (C)

223.    If n = 6, the correct sequence of filling of electrons will be

(A) ns ® np(n - 1)d ® (n - 2)f

(B) ns ® n(n - 2)f ® (n - 1)d ® np

(C) ns ® (n - 1)d ® (n - 2)f ® np

(D) ns ® (n - 2)f ® np ® (n - 1)d

Answer:: (B)

224.    If one mole of ammonia and one mole of hydrogen chloride are mixed in a closed container to form ammonium chloride gas, then

(A) DH > Du

(B) DH = Du

(C) DH < Du

(D) there is no relationship

Answer:: (C)

225.    If the  for a given reaction has a negative value, then which of the following gives the correct relationships for the values of DG° and Keq?

(A) DGo > 0; Keq < 1

(B) DGo > 0; Keq > 1

(C) DGo < 0; Keq > 1

(D) DGo < 0; Keq < 1

Answer:: (A)