11th class (FSc) chemistry Unit 7 MCQs
Chapter 7 MCQs 11th Class Chemistry
Thermochemistry:
1. In endothermic reaction, the heat content of the:
a. Products is more than that of reactants
b. Reactants is more than that of product
c. Both a and b
d. Reactants and product are equal
2. Whenever a reaction is exothermic, then it mean that:
a. The heat content of the reactants is less than those of products
b. The heat is transferred from surrounding to the system
c. The heat is transferred from system to the surrounding
d. The heat content of the product is greater than reactants
3. If an endothermic reaction is allowed to take place very rapidly in the air, the temperature of the surrounding:
a. Decreases
b. Remain constant
c. Remain unchanged
d. Increases
4. One electron is equal to:
a. 41.84 J
b. 4.184 J
c. 418.4 J
d. 0.4184 J
5. The exothermic process is:
a. Sublimation
b. Evaporation
c. Boiling
d. Combustion of methane
6. A state function which describes together internal energy and product of pressure and volume is called:.
a. Work
b. Enthalpy
c. Free energy
d. Internal energy
7. Which is not a state function:
a. Pressure
b. Enthalpy
c. Temperature
d. work
8. The number of fundamental ways of transferring energy into or out of system:
a. Three
b. One
c. Four
d. Two
9. At constant volume,qv is equal to:
a. △P
b. △H
c. △V
d. △E
10. The volume of △ H being very small, the term △ (PV) can be neglected, for the process involving:
a. Solids and gases
b. Liquid and gases
c. Liquid and solid
d. None of these
11. For a given process, the heat change at constant pressure and at constant volume are related to each other as:
a. qp>qv
b. qp=qv
c. q p = qv/2
d. qp<qv
12. The enthaply change when one mole of a substance is completely burnt in excess of oxygen is called:
a. Enthaply of neutralization
b. Enthalpy of atomization
c. Enthaply of formation
d. Enthalpy of combustion
13. Enthalpy change for the reaction CH4+2O2→CO2+2H2O is called enthalpy of:
a. Neutralization
b. Formation
c. Atomization
d. Combustion
14. Standards enthalpies are measured at:
a. 373 K
b. 273 K
c. 298 K
d. All of these
15. The total heat content of a system is called:
a. Temperature
b. Entropy
c. Internal energy
d. Enthaply
16. The change in heat energy of a chemical reaction at constant pressure is called:
a. Bond energy
b. Enthalpy change
c. Internal energy change
d. Heat of sublimation
17. Enthalpy of all elements in their standard states are:
a. Always positive
b. Unity
c. Always negative
d. Zero
18. In a bomb calorimeter, the reactions are carried out at constant:
a. Volume
b. Pressure
c. Temperature
d. None of these
19. The pressure of oxygen inside the bomb calorimeter is:
a. 25 atm
b. 100 atm
c. 20 atm
d. 50 atm
20. The net change in a chemical reaction is same whether it is brought about in two or more different ways in one or several steps. it is called:
a. Hess’ law
b. Henry’s law
c. Graham’s law
d. Charles’s law
21. Born-Haber cycle is used to determine the:
a. Lattice energy
b. Combustion energy
c. Formation energy
d. Decomposition energy
22. The highest value of lattice energy which one of these ionic compound has:
a. NaBr-728
b. Nal-690
c. NaCl-787
d. NaF-895
23. If an endothermic reaction is allowed to take place very rapidly in the air. The temperature of surrounding air is:
a. Decrease
b. Remain constant
c. Remains constant
d. Increase
24. In endothermic reaction, the heat contents of:
a. Product is more than of reactant
b. Reactant is more than of product
c. Both a and b
d. Reactants and products are equal
25. Calorie is equivalent to:
a. 4.184 J
b. 0.4184 J
c. 418.4 J
d. 41.84 J