1. 25 cm³ of sodium chloride solution has a concentration of 0.5 mol/dm³. What amount of sodium chloride does it contain?

Question 1 of 17

2. 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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3. 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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4. What is meant by the term molecular formula?

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5. State the units of molar enthalpy change.

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6. Calculate the relative formula mass(Mr) of ammonium nitrate (NH₄NO₃)

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7. Complete the following expression: amount (in moles) =

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8. A compound that contained 24.24% Carbon. 4.04% Hydrogen and 71.72% Chlorine and has a relative molecular mass of 99. Calculate the empirical formula and the molecular formula.

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9. State the expression for calculating molar volume of a gas.

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10. What are the units for amount in Chemistry?

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11. What mass of calcium bromide will fully react with 71g of chlorine?

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12. A sample of bromine contained the two isotopes in the following proportions: bromine-79 = 50.7% and bromine-81 = 49.3%. Calculate the relative atomic mass of bromine

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13. State the steps for calculating empirical formula

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14. In a chemical reaction, the overall molar enthalpy is -87 kJ/mol. Is this reaction exothermic or endothermic?

Question 14 of 17

15. To determine the formula of a metal oxide by combustion, magnesium is heated in a crucible. Why is a lid lifted from time to time?

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16. 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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17. Name this piece of lab equipment

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