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With reference to aqua regia, choose the correct option(s).(A) The yellow colour of aqua regia is due to the presence of NOCl and Cl2 (B) Aqua regia is prepared by mixing conc. HCl and conc. HNO3 in 3 : 1 (v/v) ratio(C) Reaction of gold with aqua regia produces an anion having Au in +3 oxidation state(D) Reaction of gold with aqua regia produces NO2 in the absence of air |
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Answer» Correct option (A, B, C) Explanation: (A) HNO3 + 3HCl → NOCl + Cl2 + 2H2O The nitrosyl chloride and chlorine impart yellow color to aqua regia. (B) Aqua regia is a 3 : 1 mixture of conc. HCl and conc. HNO3. (C) Gold dissolves in aqua regia to form [AuCl4]–. Au + 4H+ + NO3- 4Cl- → [AuCl4]- + NO + 2H2 (D) Air oxidises NO to NO2. Hence in absence of air, possibility of formation of NO2 is less |
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