chemical reaction chapter mcqs

 

CHAPTER 6

 

CHEMICAL REACTIONS

Q.1. All of the following are state functions except

a. P

b. V

c. q

d. H

(c)

 

Q. 2. Suppose you have a balloon of given volume, V1, containing a gas at temperature, T1. When you place the balloon in a colder room at temperature, T2, the balloon’s temperature starts to drop. What are the signs of the system’s q, w, and E for this process?

a. +q, +w, + E

b. -q, -w, + E

c. +q, -w, - E

d. –q, +w, - E

(d)

Q. 3. The melting of ice at body temperature is an endothermic process:

H2O(s) H2O(I) ΔH= +6.0kJ / mol Thus eating ice counteracts the exothermic processes of metabolizing food. How much ice (in grams) would you have to eat to counteract the energy gained by eating 28.3g of

peanuts (13 kJ/g)?

a. 78 g

b. 110 g

c. 370 g

d. 1100 g

(d)

 

Q. 4. All of the following statements are false except

a. q = H at constant T; q = E at constant V

b. q = H at constant V; q = E at constant P

c. q = H at constant P; q = E at constant V

d. q = H = E at constant P or at constant V

(c)

 

Q. 6. Calculate the standards molar enthalpy of formation of CO2(g) in the reaction:

C(g) +O2(g) CO2(g)

Given the following standard enthalpy changes:

2C(s) +O2(g) 2CO(g), ΔHo = -221kJ

2CO(g) + O2(g) 2CO2(g), ΔHo = -566kJ

a. -393.5 kJ

b. +393.5 kJ

c. +787.0 kJ

d. -787.0 kJ

(a)

 

Q. 7. All of the following chemical reactions are endothermic except

a. H2O(s) H2O(I)

b. 2H2O(g) 2H2(g) +O2(g)

c. H2O(g) H2O(I)

d. AI2O3(I) + 2Fe(I) 2AI(s) + Fe2O3(s)

(c)

 

Q. 8. All of the followings are incorrect except

a. Hvaprizaiton < Hsublimation < Hfusion < Hcondensation

b. Hfusion < Hcondensation < sublimation < Hvaporization

c. Hcondensation < Hfusion < Hvaporization < Hsublimation

d. Hcondensation < Hsublimation < Hfusion < Hvaporization

(c)

 

Q. 10. A chemist heated a balloon by supplying 600 J of heat. The balloon expands doing 200 J of

work against the atmospheric pressure. The change in internal energy of

a. -800 J

b. -400 J

c. O J

d. +400 J

(d)

 

Q. 11. Spontaneous reactions are those which

a. continue to occur once started

b. require activation energy

c. are endothermic

d. are exothermic

(a)

 

Q. 12. All of the following processes are spontaneous except

a. reaction of H2 with O2 to form H2O

b. combustion of natural gas

c. neutralization of HCI by NaOH

d. synthesis of glucose by plants

(d)

 

Q. 14. The following table provide different types of system and their examples but in irregular manner. System Example

I. Open a. water in cork fitted titration flask

II. Closed b. pigeon

III. isolated c. ice in thermos bottle

Which of the following is a best match of both columns?

a. (I, a), (II, b), (III, c)

b. (I, b), (II, a), (III, c)

c. (I, c), (II, a), (III, b)

d. (I, b), (II, c), (III, a)

(b)

 

Q. 15. Sublimation, vaporization, melting and photosynthesis all are examples of

a. chemical processes

b. physical processes

c. biochemical processes

d. endothermic processes

(d)

 

Q. 16. A mixture of ice and water contains 60g of ice and 60g of water. If 60J of heat energy is removed

from this mixture then some of the

a. water will vaporize

b. ice will sublime

c. ice will melt

d. water will freeze

(d)

 

Q. 17. Pieces of four different metals are present on a table. These metals are Na, AI, W and Ti. Their

melting points are 98, 660, 3410 and 1660 oC respectively. Metal having maximum enthalpy of

fusion is

a. Ti

b. AI

c. W

d. Na

(c)

 

Q. 18. If volume of a system is kept constant and heat is supplied to the system then

a. internal energy of the system increases and no work is done on the surrounding

b. internal energy of the system increases and work is done on the surrounding

c. no change in internal energy occurs

d. no work is done on the surrounding

(a)

 

Q. 19. Melting of ice at room temperature is

a. spontaneous exothermic process

b. spontaneous endothermic process

c. non-spontaneous exothermic process

d. non-spontaneous endothermic process

(b)

 

CHAPTER 7

CHEMICAL EQUILIBRIUM

Q. 1. At 1000 C, the equilibrium constant for the reaction of carbon monoxide and oxygen to produce

carbon dioxide is very large (Kc = 1.2 x 1022). When the reaction is at equilibrium the:

a. concentration of carbon dioxide will be much larger than one or both reactants

b. concentration of carbon dioxide will be much smaller than concentrations of both reactants

c. concentration of carbon monoxide will be much larger than the concentration of carbon dioxide

d. concentrations of both reactants must be much smaller than the concentration of carbon dioxide

(a)

 

Q. 2. A cylinder contains a unknown gas “X”. When the cylinder is heated a reddish brown color

develops. It means that the gas present in the cylinder was

a. NO2

b. N2O

c. N2O5

d. N2O4

(d)

 

Q. 3. A beaker contains a saturated solution of potassium Perchlorate. When potassium chloride (KCI) is added to this solution, some of the potassium Perchlorate is precipitated. It means that

a. KCIO4 is strong electrolyte that KCI

b. Solubility of KCIO4 is greater than that of KCI

c. Both KCIO4 and KCI are soluble in water to some extent

d. KCI is a strong electrolyte as compared with KCIO4

(d)

 

Q. 4. In salt analysis 3rd group basic radicals (Al3+, Fe3+ etc) are detected by adding NH4CI to the salt solution and then NH4OH. 3rd group radicals are precipitated as hydroxide. In this process

a. NH4CI will ionize to a lesser extent in presence of NH4CI

b. NH4CI will precipitate

c. NH4CI will react with NH4CI

d. AL3+ will precipitate as AICI3

(a)