1. Which of the following pairs can be cited as an example to illustrate the Law of multiple proportic 1) Na,0,K,O 2) ,Mg0 3) Al,O,Cr,O, 4) CO,CO,. 2. A sample of pure CO, irrespective of it's source contains 27.27% of 'C' and 72.73% of oxygen. 1,ne data support 2' 1) Law of conservation of mass 2) Law of constant proportions 4) Law of multiple proportions 3) Law of reciprocal proportions The 3. The mass of an atom of an element is 4 x 10-23 gm. It's atomic weight is 1) 0.4 2) 4 3) 16 4) 24 4. The number of moles of sucrose present in 171gms of sucrose 1) 1 2) 0.5 3) 3 4) 1.5 The weight of 0.25 mole of sodium carbonate 5. 1) 106 g 2) 26.5 g 3) 53 g 4) 25g 6. The mass of 5 x 10 19 molecules of a hydrocarbon is 2.5 mg. The hydrocarbon is 1) ,, 2) ,, 3) ,, 4) ,, 7. Which of the following contains the least number of molecules ? 1) 1g of hydrogen 2) 2g of nitrogen 3) 4g of 4) 11g of carbondioxide gen The number of molecules present in 1.12 105 cc of a gas at STP 8. 1) 6.023 x 1014 2) 3.01 x 1014 3) 6.023 1012 4), 3.01 x 1012 9. Which of the following contains the maximum number of atoms"? 1) 10g of CaCO, 2) 4g of hydrogen 3) 9g of NH NO, 4) 1.8g of C,HO, 3. EBUGAYsas 11. The number of molecules present in 6g of urea 10. The volume occupied by 2 moles of NO gas at STP 1) 11.2 Lit 2 448 Lit 3) 5.6 Lit 4) 2.8 Lit 1) 6.023 x 1023 2) 3.015 x 1023 3) 6.023 1022 4) 3.015 x 1022 12. 7.5g of a gas occupies 5.6 litres at STP. The gas is 1) NO 2) N,0 3) co 4) , 13. Among the following which one weights more 2) 10 moles of Hydrogen 1) one gram-atom of silver 3) 44.8 L of CO, at STP 4) 90 gm of water 14. The density of a gas at STP is 1.5g / L at STP. Its molecular weight is 2) 33.6 g 3) 33.6 4) 44.8 1) 22.4 15. Some statements regarding 10 grams of CaCO, are given below. Among them the correct statements are a) It is equal to 0.5 mole c) It contains 0.15 gram molecule of oxygen b) It contains 0.3 gram - atom of oxygen d) It contains 0.1 gram -atom of calcium 2) Only a,b and d are correct 4) Only a,c and d are correct 1) All correct 3) Only b,c,d are correct 16. A coin contains 80% copper. If the coin contains 6 10 atoms of copper, then the mass of the coin is (At.Wt.of copper = 64) 1) 12g %3D 2) 6g 3) 10g 4) 8g E25