11th class (FSc) chemistry Unit 7 MCQs
26. The change in heat energy of a chemical reaction at constant temperature and pressure is called:
a. Bond energy
b. Enthalpy change
c. Internal energy change
d. Heat of sublimation
27. Which of the following statement is contrary to first law of thermodynamics?
a. In an adiabatic process, work done is independent of its path
b. Energy can neither created nor destroy
c. Continuous productions of mechanical work without supplying an equivalent amount of heat is possible
d. One form of energy can be transformed into an equivalent amount of other kind of energy
28. For given process. The heat change at constant pressure and at constant volume are related to each other as:
a. pq>pv
b. pq=pv
c. pq=pv/2
d. pq<pv
29. For a given reaction NaOH+HCL → NaCl + H2O thechange in enthaply is called:
a. Heat of neutralization
b. Heat of reaction
c. Heat of combustion
d. Heat of formation
30. The net heat change in a chemical reaction is same whether it is brought about in two or more different ways one or several steps. It is known as:
a. Joule’s law
b. Henry’s law
c. Law of conservation or energy
d. Hess’s law
31. Enthalpy of neutralization of all strong acids and bases has the same value because:
a. Acids always gives H+ ions and bases OH– ions
b. Neutralization to formation of salt and water
c. The net chemical change involves the combination of H+ and OH– to form water
d. Stong acids and bases are ionic substance
32. Lattice energy of an ionic crystal is the enthalpy of:
a. Dissolution
b. Combustion
c. Formation
d. Dissociation
33. In standard enthalpy of atomization, heat of the surrounding.
a. Increases then decreases
b. Remain unchanged
c. Decrease
d. Increase
34. □H will be given a negative sign in:
a. Dissociation reactions
b. Exothermic reactions
c. Endothermic reactions
d. Decomposition reactants
35. Lattice energy on an ionic crystal is the enthalpy of:
a. Dissolution
b. Combustion
c. Formation
d. Dissociation
36. Heat of formation (DHro) for CO2 is:
a. -294KJ/mole
b. -394 KJ/mole
c. -390KJ/mole
d. +394 KJ/mole
37. Reactant have high energy than product in:
a. Photochemical reactions
b. Exothermic reactions
c. Non-spontaneous reactions
d. Endothermic reactions
38. Combustion of graphite to form CO2 can be done by two ways. Reaction are given as follows:
a. H = -393.7 KJmol-1
b. C+O2→ CO2
c. H =?
d. C+1/2O2 → CO
39. 2H2 + O2 →2H2O □ H = + 285.5 KJ mole-1
a. -202.5 KJ/mol
b. 205.5 KJ/mol
c. 1 KJ/mol
d. Zero KJ/mol
40. What will be enthalpy of formation of CO?
a. 110 KJ mol-1
b. -676 KJ molc
c. 676 KJ mol-1
d. -110 KM mol-1
41. The equation that represents standard enthalpy of atomization of hydrogen is:
a. 1/2 H2(g) → H(g) +218 KJmol-1
b. 1/2 H2O(i) → H2(g) + 1/2 O(g)
c. 1/2 H2(g) → H(g) +-218 KJmol-1
d. 1/2 H2O(i) → H2(g) – 1/2 O(g)
42. 1/2 H2(g) □ H= 218KJ mol-1 in this reaction, □ H will be called
a. Enrthalpy of formation
b. Enthalpy of atomization
c. Enthalpy of dissociation
d. Enthalpy of decomposition
43. The equation that reprents standard enthalpy of atomization of hydrogen is:
a. 1/2 H2(g) → H(g) +218 KJmol-1
b. 1/2 H2O(i) → H2(g) + 1/2 O(g)
c. 1/2 H2(g) → H(g) +-218 KJmol-1
d. 1/2 H2O(i) → H2(g) – 1/2 O(g)
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