31.In the extraction of Cu, the metal is formed in the bessemer converter due to the reaction : A) $Cu_{2}S + 2Cu_{2}O \rightarrow 6Cu + SO_{2}$ B) $Cu_{2}S \rightarrow 2Cu+S$ C) $Fe + Cu_{2}O\rightarrow 2Cu + FeO$ D) $2Cu_{2}O\rightarrow4Cu + O_{2}$ View Answer Report DiscussAnswer: Option DExplanation:Decomposition of carbonates and hydrated oxides
32.The reagent (s) which can be used to distinguish acetophenone from benzophenone is (are) A) 2,4-dinitrophenylhydrazine B) aqueous solution of $NaHSO_{3}$, C) benedict reagent D) $I_{2}$and$Na_{2}Co_{3}$ View Answer Report DiscussAnswer: Option DExplanation:I2 and Na2CO3, react with acetophenone (C6H5COCH3) to give yellow ppt. of CHI3 but benzophenone (C6H5COC6H5) does not and hence can be used to distinguish between them.
33.For the process H2O(l) (1 bar, 373 K) → H2O(S) (1 bar,373 K), the correct set of thermodynamic parameters isΔ A) $\triangle G = 0, \triangle S = +ve$ B) $\triangle G = 0, \triangle S = -ve$ C) $\triangle G = +ve, \triangle S = 0$ D) $\triangle G = -ve, \triangle S = +ve$ View Answer Report DiscussAnswer: Option AExplanation:Since liquid is passing into the gaseous phase so entropy will increase and at 373 K during the phase transformation it remains at equilibrium. So, ΔG = 0.
34.Which of the following compounds is formed . when a mixture of K2Cr2O7 and NaCl is heated with conc. H2SO4 ? A) $CrO_{2}Cl_{2}$ B) $CrCl_{3}$ C) $Cr_{2}(SO_{4})_{3}$ D) $Na_{2}CrO_{4}$ View Answer Report DiscussAnswer: Option AExplanation:$K_{2}Cr_{2}O_{7}+4NaCl+6H_{2}SO_{4}\xrightarrow{Heat}2CrO_{2}Cl_{2}+6NaHSO_{4}+3H_{2}O$
35.The chirality of the compound A) R B) S C) E D) Z View Answer Report DiscussAnswer: Option AExplanation:Clockwise rotation. Hence configuration is R. If the eye travel in a clockwise direction, the configuration is R as the order of priority is Br > Cl > CH3 > H
