JEE Main levelOne or more correct optionsDifficulty 2 of 3rx143
Use Cu = 63.5 and molar volume 22.4L/mol at STP. 6.35g of Cu reacts completely with nitric acid by 3Cu+8HNOX33Cu(NOX3)X2+2NO+4HX2O (dilute) or Cu+4HNOX3Cu(NOX3)X2+2NOX2+2HX2O (concentrated). Select the correct statement(s).
ADilute acid gives 1.49 L of NO at STP
BConcentrated acid gives 4.48 L of NOX2 at STP
CConcentrated acid consumes 0.40 mol of HNOX3
DDilute acid consumes 0.20 mol of HNOX3
Answer: A, B, C
n(Cu)=0.1. Dilute: NO=0.1×2/3 mol, i.e. 1.49 L (A true); HNOX3=0.1×8/3=0.267 mol, so D (0.20) is false. Concentrated: NOX2=0.2 mol, i.e. 4.48 L (B true); HNOX3=0.1×4=0.40 mol (C true).