1. Use Q=mcΔT and c=4.18J/°C/g. A spatula of sodium fluoride is put into a boiling tube with 25cm³ of water. The temperature drops from 22.0°C to 18.6°C. What is the total heat energy change?

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2. In a chemical reaction, 250 kJ/mol is taken to break all the bonds and 280 kJ/mol is released when new bonds are formed. What is the overall molar enthalpy of the reaction?

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3. What is meant by the term molecular formula?

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4. What is the meaning of the term Molar Volume?

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5. In the thermal decomposition of calcium carbonate, we might expect 50g of calcium carbonate to produce 28g of calcium oxide. If instead only 24g of calcium oxide is produced, what is the percentage yield?

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6. What mass of carbon dioxide is produced when 24g of carbon undergoes completely combustion?

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7. What is the meaning of the word mole in Chemistry?

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8. Describe how to carry out an acid-alkali titration

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9. A sample of carbon contained 98.90% carbon-12 and 1.10% carbon-13. Calculate the relative atomic mass of carbon

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10. A beaker of 1.5 mol/dm³ calcium chloride solution contains 0.3 mol of calcium chloride. What is the volume of the solution?

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11. A graph shows the solubility of sodium chloride in water at 50°C is 34g/100g. At that temperature, what mass of sodium chloride will dissolve in 200g water?

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12. State the units of molar enthalpy change.

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13. What is the equation linking moles, Mᵣ and mass

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14. Calculate the relative formula mass(Mr) of ethanol (C₂H₅OH)

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15. Work out the empirical formula of an oxide of chlorine contains 7.1 g of chlorine and 1.6 g of oxygen.

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16. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid used?

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17. An oxide of nitrogen contains 26% nitrogen and 74% oxygen and has a relative molecular mass of 108. Find the empirical and molecular formulae for the oxide.

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