Thermochemistry MCQs


Note: All MCQs related to Thermochemistry will be updated on this page.Answers to the MCQs are given in the comments section.

[page][item] 1-The process which once started will continue to happen without the intervention of outside sources is called
A Non-spontaneous process
B Continuous process
C Isobaric process
D Spontaneous process

2-Melting of ice at room temperature, rusting of iron and combustion of methane are
A Spontaneous and exothermic processes
B Spontaneous and endothermic processes
C Spontaneous and reversible processes
D Spontaneous processes

3-Ice can be melted at a room temperature below than 0C by applying pressure. The process is an example of a
A Physical change
B Non-spontaneous physical change
C Spontaneous physical change
D Non-spontaneous chemical change

4-If heat is supplied to the system and work is done on the system then first law of thermodynamics will take the form
A dE=q+w
B dE=q-w
C dE=-q+w
D dE=-q-w

(entrytestpractice.blogspot.com)

5-Applying first law of thermodynamics to a gaseous system in which heat is released by the system and work is done on the system we get
A dE=q+w
B dE=q-w
C dE=-q+w
D dE=-q-w

6-Heat supplied to a system at constant pressure increases its
A Internal energy
B Volume
C Enthalpy
D Temperature

7-Applying first law of thermodynamics to a process in which volume of the gaseous system remains constant we get
A q=dE+w
B q=dE
C q =dH
D q=dE-w

8-Conditions under which standard enthalpy changes are measured are
A 273 K and 1 atm
B 0 C and 1 atm
C -273 C and 1 atm
D 25 C and 1 atm

9-The enthalpy change during the formation of one mole of a compound from its elements in their standard states is called
A Standard heat of reaction
B Standard heat of formation
C Standard heat of combustion
D Standard heat of neutralization

(entrytestpractice.blogspot.com)

10-All of the following processes do not represent hydration except
A K+(g) + Cl-(g)------->KCl(s)
B Na+(g) +I-(g)--------->NaI(s)
C K+(g) + Br-(g)--------->KBr(aq)
D Na+(g) +Cl-(g)--------->NaCl(s)

[/item][item] 11-The enthalpy change during the dissolution of one mole of gaseous ions in water to produce infinitely dilute solution is known as
A Enthalpy change of solution
B Enthalpy change of hydration
C Enthalpy change of combustion
D Enthalpy change of neutralization

12-Heat of solution dH(sol) is related to lattice energy dH(L.E) and heat of hydration dH(h) by the equation
A dH(h) = dH(sol) - dH(L.E)
B dH(h) = dH(sol) + dH(L.E)
C dH(sol) = dH(h) + dH(L.E)
D dH(sol) = dH(L.E) - dH(h)

13-"The amount of heat evolved or absorbed in a chemical reaction is the same no matter the reaction takes place in one step or several steps" is statement of
A First law of thermodynamics
B Hess's law
C Law of mass action
D Raoult's law

14-All of the following processes do not represent ionization of sodium except
A Na(g)------->Na+(aq) +e
B Na(s)-------->Na+(g) +e
C Na(l)----->Na+(g)+e
D Na(g)-------->Na+(g) +e

(entrytestpractice.blogspot.com)

15-Suppose you have a balloon of given volume V1, containing a gas at temperature T. 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' q , w and dE for this process?
A +q, +w, +dE
B -q, -w, +dE
C +q, -w, -dE
D -q, +w, -dE

16-The melting of ice at room temperature is an endothermic process:
H2O(s)---->H2O(l)  dH=+6.0 kJ/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 28.3 g of peanuts (13 kJ/g)?
A 78 g
B 110 g
C 370 g
D 1100 g

17-In which of the following general chemical systems is work done on the surrounding and heat transferred from  the surroundings to the system?
A A(g) + B(g) ---------> AB(g)   q= -
B AB(g)------>A(g) + B(g)         q=+
C AB(g) + CD(g)--------> CB(g) + AD(g)    q=+
D A(g) +A(g)---------A2(g)        q=+

18-SO2(s)------->SO2(g) [32.3 kJ/mol]
SO2(l)------->SO2(g) [24.9 kJ/mol]
amount of energy for SO2(l)---->SO2(s) is
A 57.2 kJ/mol
B 7.4 kJ/mol
C -7.4 kJ/mol
D -57.2 kJ/mol

19-Which process is not endothermic?
A H2O(s)---->H2O(l)
B 2H2O(g)------>2H2(g) + O2(g)
C H2O(g)------->H2O(l)
D Al2O3(l) + 2Fe(l)-------> 2 Al(s) + Fe2O3(s)

(entrytestpractice.blogspot.com)

20- 3/2O2(g) +2B(s)------>B2O3(s),  dH=-1264 kJ/mol;
O3(g) +2B(s)------->B2O(s),  dH=-1406 kJ/mol.
Calculate the enthalpy change for the reaction converting oxyden(O2(g)) to ozone O3(g) at 298 K and 1 atm.          
3/2O2(g)---->O3(g)
A -1264 kJ
B -2670 kJ
C -142 kJ
D +142 kJ

[/item][item] 21-Which of the following sequences of the dH associated with the phase changes of a particular substance is correct?
A dH(vaporization) < dH(sublimation) < dH(fusion) < dH(condensation)
B dH(fusion) < dH(condensation) < dH(sublimation) < dH(vaporization)
C dH(condensation) < dH(fusion) < dH(vaporization) < dH(sublimation)
D dH(condensation) < dH(sublimation) < dH(fusion) < dH(vaporization)

22-Which of the following is not a spontaneous process?
A Reaction of H2 with O2 to form H2O
B Combustion of natural gas
C Neutralization of HCl bu NaOH
D Synthesis of glucose by plants

23-Water can be produced in laboratory by the reaction  2H2 + O2---->2H2O. If H(f) is the heat of formation of H2O and H(r) is the heat of reaction then
A H(f)=H(r)
B H(f)=H(r)/2
C H(r)=H(f)/2
D H(f)=2H(r)

24-Sublimation, vaporization, melting and photosynthesis all are examples of
A Chemical processes
B Physical processes
C Biochemical processes
D Endothermic processes

 (entrytestpractice.blogspot.com)

25-X represent an unknown compound... X(s)---->X(g) [200 kJ/mol];
X(s)----->X(l) [8 kJ/mol]; X(l)------>X(g) [?}.
Calculate unknown enthalpy change.
A 192 kJ/mol
B 208 kJ/mol
C 16 kJ/mol
D 400 kJ/mol

26-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
A Some of the water will vaporize
B Some of the ice will sublime
C Some of the ice will melt
D Some of the water will freeze

27-Zinc powder is sprinkled on aqueous solution of copper sulfate. Copper sulfate solution is decolorized. This is a
A Synthesis
B Decomposition
C Spontaneous process
D Non-spontaneous process

28-Dissolution of sodium chloride in water is a
A Non-spontaneous exothermic process
B Non-spontaneous endothermic process
C Spontaneous exothermic process
D Spontaneous endothermic process

29-Calorimeter is an apparatus used for the measurement of
A Mechanism of the reaction
B Order of the reaction
C Heat of the reaction
D Stoichiometry of the reaction

(entrytestpractice.blogspot.com)

30-Born-Haber cycle is used for the measurement of
A Potantial energy
B Kinetic energy
C Chemical energy
D Lattice energy

[/item][item] 31-In the equation X=E+PV "X" represents
A Entropy of the system
B Enthalpy of the system
C Gas constant
D Heat lost by the system

32-Thermochemistry is the study of chemical reaction accompanying
A Heat change
B Rate change
C Mass change
D Volume change

33-When a bond breaks
A Heat is evolved
B Heat is absorbed
C No change in heat contents takes place
D Temperature increases

34-Which of the following is an endothermic reaction
A C(g) + O2(g)------>CO2(g)   dH= -3904 kJ/mol
B H2(g) +1/2O2 ------->H2O(g)   dH= -286 kJ/mol
C N2(g) + 3H2(g)-------->2NH3(g)  dH = -92 kJ/mol
D N2(g) + O2(g) ------------>2NO(g)  dH= +130 kJ/mol

(entrytestpractice.blogspot.com)

35-Which one of the following is not a spontaneous reaction
A Flow of water from higher to lower level
B Neutralization of a strong acid with strong base
C When a piece of Zn is added to the blue copper sulfate solution the color disappears
D Formation of nitric oxide, NO, from N2 and H2 at room temperature

36-Which of the following is not a state function?
A Pressure
B Temperature
C Enthalpy
D Amount of substances

37-N2 and O2 are present in air but they do not react chemically at ordinary conditions of temperature and pressure because it is a
A Spontaneous reaction
B Reversible reaction
C Exothermic reaction
D Non-spontaneous reaction

38-Burning of coal in air is initiated by a spark and it is an example of a spontaneous reaction because
A Burning of coal in air releases large amount of energy
B Burning of coal is an endothermic process
C Coal and air react giving reversible reaction
D None of the above

39-A sample of matter under examination in laboratory of unit consideration in the classroom is called
A Sorrounding
B System
C Substance
D State function

(entrytestpractice.blogspot.com)

40-A microscopic property of a system which describes the initial and final state of the system is called
A Physical property
B Chemical property
C Energy of system
D State function
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