1. 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?

Question 1 of 17

2. State the expression for calculating molar concentration

Question 2 of 17

3. Name this piece of lab equipment

Question 3 of 17

4. 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.

Question 4 of 17

5. 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?

Question 5 of 17

6. Calculate the relative formula mass(Mr) of calcium carbonate (CaCO₃)

Question 6 of 17

7. A sample of hydrogen chloride gas has a volume of 48 dm³. What amount of hydrogen chloride is this?

Question 7 of 17

8. Complete the following expression: mass =

Question 8 of 17

9. 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?

Question 9 of 17

10. Use Q=mcΔT and c=4.18J/°C/g. 25cm³ of sulfuric acid is put into a boiling tube. The starting temperature is 21°C. A spatula of iron filings is added. After a while the temperature reaches 33°C. What is the total heat energy change?

Question 10 of 17

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

Question 11 of 17

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

Question 12 of 17

13. What is meant by the term molecular formula?

Question 13 of 17

14. State the units of molar enthalpy change.

Question 14 of 17

15. 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?

Question 15 of 17

16. What is the empirical formula of a compound in which 0.48 g of carbon combines with 0.08 g of hydrogen and 0.64 g of oxygen?

Question 16 of 17

17. 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

Question 17 of 17


 

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