SOME BASIC CONCEPTS OF CHEMISTRY Quiz 2 1. 1 atomic mass unit is defined as : (A) a mass exactly equal to one-twelfth the mass of 12 C-atom (B) mass of one mole of substance in grams (C) mass of 1 atom which is equal to 12 carbon-12 atom (D) mass of one atom which is equal to one carbon-12 atom 2. The Law of Conservation of mass was given by: (A) Lavoisier (B) J. Proust (C) Dalton (D) J.L. Gay Lussac 3. A substance is prepared by adding 20g of a substance 'A' to 180g of water. What is the mass percent of the solute? (A) 10% (B) 1% (C) 0.1% (D) 11.11% 4. A compound contains 4%H , 60.5%C and 35.5%Cl .What is its Empirical formula? (A) C₅H₄Cl (B) C₅H₂Cl (C) C₄H₅Cl (D) C₄H₅Cl₂ 5. The Molarity of NaOH in the solution prepared by dissolving its 20g in the enough water to form 500ml of the solution is____ (A) 40 M (B) 4 M (C) 1 M (D) 0.04 M 6. _______ is defined as the number of moles of solute in one litre of the solution. (A) Molarity (B) Molality (C) Formality (D) Normality 7. The volume of a gas (at fixed P and T) is proportional to the number of moles (or molecules of the gas present) represents______. (A) Boyle's Law (B) Charles' Law (C) Dalton's Law (D) Avogadro Law 8. Molality is defined as______ (A) the number of moles of solute present in one litre of the solution. (B) the number of moles of solute present in one gram of the solvent. (C) the number of moles of solute present in one kg of the solvent. (D) the number of moles of solvent present in one liter of solute. 9. 2.5×1.25 = (A) 3.125 (B) 3.12 (C) 3.1 (D) 3.1250 10. How many significant figures are present in 0.0052 ? (A) 2 (B) 4 (C) 5 (D) 1 11. Molecular mass of sucrose is: (A) 90 (B) 180 (C) 342 (D) 240 12. The concentration of a substance or amount of substance present in its given volume can be expressed in: (A) Mole fraction (B) Molarity (C) Molality (D) Any of the above 13. How much volume of concentrated 1M NaOH solution can be taken which contains 0.2 moles of NaOH? (A) 5 L (B) 0.2 ml (C) 200 ml (D) 5 ml 14. How many moles of methane are required to produce 11g CO₂ after combustion? (A) 0.25 (B) 0.5 (C) 1 (D) 1.5 15. Choose the correct option: a) All non-zero digits are significant.b) Zeros between 2 non-zero digits are significant.c) Zeros preceding to first non-zero digit are significant.d) Zeros at the end or right of a number are significant provided they are on the right side of the decimal point. (A) all are correct (B) a and b are correct (C) a and b are correct (D) only c is incorrect 1 out of Time is Up! Time's up
