Energy Changes in Chemical Reactions

Chemistry Board Question
Chapter Eleven
 
Energy Changes in Chemical Reactions
Short Question
1. i) What is called exothermic reaction? State an example. (SB-01, DB-05) 2
 ii) What is meant by endothermic reaction? State with example. (DB-04) 2
 iii) What is meant by exothermic and endothermic reaction? Give an example for each type. (CB-04, CtgB-00, RB-02) pre-08 2
2. The bond energies of CH, CCl, ClCl and HCl are 414, 326, 244 and 431 KJ mole1 respectively. Calculate H of the reaction mentioned below. CH4(g)+Cl2(g) = CH3Cl(g)+HCl(g) (CB-03, CtgB-04, SB-04) 2
3. In the reaction H2(g)+ O2(g)  H2O (g), the bond energy of Hydrogen atoms in Hydrogen molecule is 435 KJ per mole. The bond energy of two oxygen atoms in oxygen molecule is 498 KJ per mole. The bond energy of one oxygen-hydrogen in water molecule is 464 KJ per mole. Find out the value of H of the above reaction. (CtgB-03) 2
4. What is an spectator ion? (DB-01) 1
5. Give an example of endothermic reaction. 1
6. What is the cause of change of heat in the chemical reaction? (CtgB-03) 1
7. What do you mean by thermochemical equation? (RB-05) 2
8. i) What is meant by heat of combustion and heat of solution? (CB-05) 1+1=2
 ii) What is heat of combustion? Why heat is evolved in all combustion reaction? (RB-04, BB-04) 1+1=2
9. What are the source of the change of energy in the chemical reaction. (BB-02) 2
10. i) What is H? Express it with an equation. (CB-05) 2
 ii) What is meant by H? When it becomes positive and negative? (RB-99, DB-02, JB-05) 2
11. Write down the significance of H with a thermochemical reaction. (CtgB-01) 2
12. i) Explain why heat of neutralisation is constant for an acid and base. (JB-05) 2
 ii) The heat of neutralization of a strong acid by a strong base is 57.3 KJ- Explain with the example. (DB-00, SB-05, CtgB-02) test 08 2
13. What is neutralization reaction? State with example. 2
14. i) What is gram equivalent weight of an acid? (SB-02, JB-05) 2
 ii) What is the mass in gram of one gram equivalent weight of sulphuric acid (CtgB-02). 1
 iii) What is meant by thermochemical equation? iv) Write with the example. (SB-05, JB-04, CB-02, BB-02) 2
15. Write the significance of the equation: 2H2+O2=2H2O ; H = 484KJ mole1 (JB-04) 2
16. What do you mean by Galvanic Cell? (RB, CB-99, 01) 2
Broad Question
17. Write down the reactions that happened in the Daniel Cell. (CtgB-04) 2
18. i) Discuss with diagram the preparation and working principle of the Galvanic Cell. (BB-05) 4
 ii) Write down the preparation process and ionic reaction of Daniel Cell with the labelled diagram. (DB-03, 01) 3
19. Describe the preparation of Daniel Cell showing its chemical reaction for the production of electricity with diagram. (JB-04) 2
20. What is heat of neutralization? Why the heat of neutralization of a strong acid and strong base is constant? (CtgB-02) 3
21. i) Describe the preparation and working principal / mode of action of Dry Cell with Figure. (RB-02, CB-02) 3
 ii) What is the advantage of using the Dry cell? (JB-00) 1
 iii) Dry cell becomes useless after using for some days- Explain why? 2
22. What is meant by heat of combustion, heat of solution and heat of neutralisation? Explain with examples. (JB-03) 3
23. What are the causes of change of heat energy in chemical reactions? Write with the help of example. (DB-02)Pre08 3
24. i) What is meant by Leclanche Cell? Write down the ionic working process and use of a Leclanche Cell. (BB-01, DB-01) 4
 ii) Describe the preparation and the working principle of Leclance Cell. (SB-02) 2