1. CHEMISTRY DEPARTMENT WAID ACADEMY AVOGADRO AND THE MOLE

2. The mass of one mole of sodium is 23 g. What is the mass of one sodium atom? 1.6.02 10 23 g 2.6.02 10 -23 g 3.3.82 x 10 -24 g 4.3.82 x 10 -23 g :30

3. What volume of oxygen, in litres, is required for the complete combustion of 1 litre of butane (C 4 H 10 )? 1.1 litres 2.4 litres 3.6.5 litres 4.14 litres :30

4. Which of the following has the same volume as 32 g of sulphur dioxide (SO 2 ) gas? (All volumes are measured under the same conditions of temperature and pressure). 1.2 g of helium gas. 2.2 g of hydrogen gas. 3.20 g of neon gas. 4.32 g of oxygen gas. :30

5. The density of chlorine gas is found to be 3.00 g l -1. Under the experimental conditions, the molar volume, in litres is 1.11.8 2.22.4 3.23.7 4.35.5 :30

6. Avogadro's constant is the same as the number of 1.molecules in 1 mole of oxygen gas. 2.atoms in 1 mole of hydrogen gas. 3.ions in 1 mole of NaCl. 4.electrons in 1 mole of helium gas. :30

7. 160 g of calcium contains as many atoms as 1.24 g of carbon. 2.92 g of sodium. 3.160 g of silver. 4.256 g of sulphur. :30

8. From the equation below 2KNO 3 (s)  2KNO 2 (s) + O 2 (s) Calculate the volume of oxygen formed when 0.05 mole of potassium nitrate decomposes. Take the molar volume of a gas to be 24 l mol -1. 1.0.1 litres 2.0.2 litres 3.0.4 litres 4.0.6 litres :30

9. The number of ions in 1 mol of copper(II) phosphate, Cu 3 (PO 4 ) 2, is 1.1 2.2 3.4 4.5 :30

10. What volume of gas, in cm 3, would be obtained by the reaction between 100cm 3 of ammonia gas and excess copper(II) oxide? 2NH 3 + 3CuO  3Cu + N 2 + 2H 2 O 1.50 2.100 3.200 4.400 :30

11. A mixture of magnesium bromide, MgBr 2, and magnesium sulphate, MgSO 4, is known to contain 3 mol of magnesium and 4 mol of bromide ions. How many moles of sulphate ions are present? 1.1 2.2 3.3 4.4 :30