Q1. X gm of a certain oxide of nitrogen was slowly passed over heated copper to yield CuO and N2 gas. The increase in the weight of copper was 5.33 gm 4 litre of N2 gas at 14 C and 754 mm of Hg was also 0 obtained. What is the formula of the oxide. (A (B) NO2 (C) NO (D) N2O Q2. CN– is oxidised by NO – in presence of acid : aCN– + bNO – + cH+ (a + b) NO + aCO + c H O 3 What are the values of a, b, c in that order. 2 2 2 (A) 3, 7, 7 (B) 3, 10, 10 (C) 3, 10, 7 (D) 3, 7, 10 Q3. One gram of Na3AsO4 is boiled with excess of solid KI in presence of strong HCl. The iodine evolved is absorbed in KI solution and titrated against 0.2 N hypo solution. Calculate the volume of thiosulphate hypo used. (At. wt. of As = 75) (A) 48.1 ml (B) 24.7 ml (C) 38.4 ml (D) 30.3 ml Q4. How many grams of Zn of 90% purity would be needed to reduce 8.5 gm of NaNO3 in presence of alkali. (At. wt. of Zn = 65.4) (A) 32.2 gm (B) 19.8 gm (C) 29.1 gm (D) 23.11 gm Q5. 7gm of a mixture of KClO3 and KCl are strongly heated, 2.50gm of O2 is produced. The residue on analysis proves to be only KCl. Calculate the weight fraction of KCl in the original mixture. (A) 0.0886 (B) 0.123 (C) 0.886 (D) 0.213 Q6. S O 2– ion is oxidised by S O 2– ion, the products are S O – – and SO – – ions. What volume of 0.25 M 2 3 2 8 4 6 4 thiosulphate solution would be needed to reduce 1 gm of K2S2O8. (A) 36.92 ml (B) 32.69 ml (C) 29.63 ml (D) 62.93 ml Q7. An element forms two different sulphates in which its weight % is 28 and 37. What is the ratio of oxidation numbers of the element in these sulphates. (A) 1 : 2 (B) 1 : 3 (C) 2 : 1 (D) 3 : 2 Q8. 12 gm urea (NH2CONH2) was treated with excess nitrous acid. The following reaction occurred. NH CONH + 2HNO CO + 2N + 3H O 2 2 2 2 2 2 The gases evolved were passed through aqueous KOH solution and the final volume of the remaining gas was measured at STP. The volume of the remaining gas will be (A) 44.8 ml (B) 89.6 ml (C) 134.4 ml (D) 13.4 ml Q9. The reaction between Yttrium metal and dilute HCl produces H (g) and Y3+ ions. The molar ratio of Y used to hydrogen produced is (A) 1 : 2 (B) 2 : 1 (C) 2 : 3 (D) 3 : 2 Q10. The number of moles of Cr O 2– needed to oxidize 0.136 equivalents of N H + by the reaction is – 2 7 2 5 N H + + Cr I – – N + Cr3+ + H O 2 5 2 7 2 2 (A) 0.136 (B) 0.272 (C) 0.816 (D) 0.0227 Q11. The density of liquid ethanol is 0.7893 g/ml at 200C. If 1.2 mol of ethanol are needed for a particular experiment, what volume of ethanol should be measured out. (A) 55 ml (B) 58 ml (C) 70 ml (D) 79 ml Q12. A 10gm sample of a mixture of Calciumchloride and sodium chloride is treated with Na2CO3 to precipitate the calcium as calcium carbonate. When CaCO3 is ignited 1.62 gm CaO is obtained. The % by mass of CaCl2 in the original mixture is (A) 15.2% (B) 32.1% (C) 21.8% (D) 11.07% Q13. The moles ofAmmonium sulphate needed to react with one mole of MnO2 in acidic medium in a reaction giving MnSO4 and (NH4)2S2O8 is (A