1. 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 1 of 16

2. What is meant by the term exothermic?

Question 2 of 16

3. In an exothermic reaction, which is greater: the energy taken in when breaking bonds or the energy released when bonds are made?

Question 3 of 16

4. In a combustion calorimetry experiment, 0.78g of ethanol (C₂H₅OH) produced 12,540 J of heat energy. Calculate the molar enthalpy change.

Question 4 of 16

5. Are combustion reactions exothermic or endothermic?

Question 5 of 16

6. What is meant by the term endothermic?

Question 6 of 16

7. 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?

Question 7 of 16

8. 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 8 of 16

9. When a solid dissolves, is this process exothermic or endothermic?

Question 9 of 16

10. What does this diagram represent?

Question 10 of 16

11. Assuming bond energies in kJ/mol: H-C 412, C-C 348, O-H 463, C-O 360, C=C 612. Calculate the molar enthalpy change for the reaction: ethanol → ethene + water

Question 11 of 16

12. State the units of molar enthalpy change.

Question 12 of 16

13. What does this diagram represent?

Question 13 of 16

14. Explain why experimental values of enthalpy change differ from theoretical values

Question 14 of 16

15. Explain, in terms of making and breaking bonds, why a reaction could be exothermic

Question 15 of 16

16. In a calorimetry experiment to investigate the heat energy released by the combustion of ethanol, why should the water in the calorimeter be stirred?

Question 16 of 16


 

Related Posts: