If you are looking MCQs for 1st year Chapter Five "Thermochemistry" MCQs Question Answers with solutions you are here on right website. On this Page you will learn Chapter Five objective type solved Questions with solutions. All of these chapter wise first Year Chemistry question answers are helpful for upcoming exams and tests preparations. These MCQs are also helpful for entry tests.
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| 1st Year Chemistry MCQs Thermochemistry Quiz Test |
You will learn in this Chapter:
- Spontaneous and non-spontaneous reaction
- System, Surrounding and State Function
- Internal Energy
- 1st law of Thermodynamics
- Enthalpy of a reaction
- Measurement of Enthalpy
- Hess’s Law
- Born-Haber Cycle
Q.1: Enthalpy of neutralization of strong acids and strong bases have the same values because?
- Neutralization leads to the formation of salt and water
- Strong acids and bases are ionic substances
- Acids always give rise to H+ and bases always furnish OH-1 ions
- The net change involves the combination of H+ and OH-1 ions form water
D
Q.2: For an endothermic reaction, enthalpy of reactants?
- Is smaller than that of the products
- Is greater than that of the products
- Is equal to that of the products
- Must be greater or smaller than that of the products
A
Q.3: Which of the following has a positive value of enthalpy?
- Neutralization
- Atomization
- Combustion
- All of the above
B
Q.4: The net heat change in the chemical reaction is the same whether it is brought about in two or more different ways in one or several steps. It is known as?
- Henry’s law
- Hess’s law
- Joule’s principal
- Law of conservation of energy
B
Q.5: Hess’s law is analogous to?
- Law of heat summation
- Law of increasing entropy
- Law of heat exchange
- 1st law of thermodynamics
A
Q.6: NaOH + HCl → NaCl + H2O
Enthalpy change in the above reaction is called?
Enthalpy change in the above reaction is called?
- Enthalpy of reaction
- Enthalpy of neutralization
- Enthalpy of formation
- Enthalpy of combustion
B
Q.7: A hypothetical reaction X → 2Yproceeds by the following sequence of steps:
1/2X → Z ∆H = q1
Z → 2W ∆H = q2
W → 1/2Y ∆H = q3
The values for the ∆H of the reaction is?
1/2X → Z ∆H = q1
Z → 2W ∆H = q2
W → 1/2Y ∆H = q3
The values for the ∆H of the reaction is?
- q1 + q2 + q3
- 2(q1 + q2 + q3)
- 2q1 + 2q2 + 3q3
- 2(q1 + q2 + q3)
C
Q.8: Calories are equivalent to?
- 0.4184 J
- 40.18 J
- 4.184 J
- 418.4 J
C
Q.9: The values of ∆H for the process I(g) + e-1 → I-1(g) is?
- > 0
- 0
- < 0
- None of the above
C
Q.10: The enthalpy of formation of a compound is?
- Positive
- Either positive or negative
- Negative
- None of the above
B
Q.11: What is correct about the heat of combustion?
- It is positive in some cases while negative in other
- It is applicable to gaseous substances only
- It is always negative
- It is always positive
C
Q.12: What is not correct about ∆Hf??
- Its value gives an idea about the relative stability of reactants and the products
- It is always negative
- Values depend upon the nature of bonds
- Its value can be greater or less than zero
B
Q.13: If an endothermic reaction is allowed to take place very rapidly in air, the temperature of the surrounding air will??
- Remains constant
- Decrease
- Increase
- Either increase or decrease
D
Q.14: When a solid melts, there is?
- Increase in entropy
- The decrease in internal energy
- Increase in enthalpy
- Both a and b
D
Q.15: The heat of reaction depends upon?
- The temperature of the reactants
- Physical states of the reactants and the products
- Both a and b
- Path of the reaction and the temperature
B
Q.16: The exothermic process is?
- Evaporation
- Respiration
- Sublimation
- Boiling
B
Q.17: During an exothermic or endothermic reaction which one of the following formulae is used to calculate the amount of heat evolved or absorbed-----?
- ∆H = ∆E + PV
- ∆p = ∆H
- ∆E = q + w
- q = m x s x ∆T
D
Q.18: Most of the reactions which give stable products are?
- Endothermic
- Isothermal
- Exothermic
- None of these
C
Q.19: The measurement of enthalpy change at standard conditions means that we should manage the measurement that------?
- 24°C at 1 atm
- 0°C at 1 atm
- 25°C at 1 atm
- 100°C 1 at atm
B
Q.20: The total heat content of a system is called-------?
- Internal energy
- Enthalpy
- Entropy
- All of these
B
Q.21: The enthalpies of all elements in their standard states are?
- Unity
- Always +ve
- Always –ve
- Zero
D
Q.22: A state function which describes together the internal energy and product of pressure and volume is called-------?
- Enthalpy
- Internal energy
- Work
- Kinetic energy
A
Q.23: The enthalpy change for the reaction C2H2 + 5/2 O2 → 2CO2 + H2O is brown as enthalpy of?
- Formation of CO2
- Combustion of C2H2
- Fusion of C2H2
- Vaporization of C2H2
B
Q.24: The value of ∆V is very small. The term P∆V can be neglected for the process involving?
- Liquid and gas
- Liquid and solid
- Solid and gases
- None of these
B
Q.25: The lattice energy of NaCl is?
- 787 J/mole
- 780 kJ/mol
- 790 kJ/mol
- -787 kJ/mole
D
Q.26: Decomposition of H2O is?
- Endothermic reaction
- Exothermic reaction
- Nuclear reaction
- Zero nuclear reaction
A
Q.27: According to Hess’s Law, the enthalpy change for a reaction?
- Depends on path
- The sum of ∆E and ∆H
- Independent of the path
- None of these
C
Q.28: Enthalpy of formation of one mole of an ionic compound from gaseous ion under standard condition is called------?
- Gibb’s energy
- Lattice energy
- Bond energy
- All of these
B
Q.29: Choose from the following the correct statement about Born Harbor cycle?
- Born Harbor cycle is different from Hess’s law
- The energy changes in a cyclic process is not zero
- The lattice energy of crystalline substances can be calculated easily
- None of these
C
Q.30: Change in enthalpy of ∆H a system can be calculated by the following relationship?
- ∆H = ∆E-PV
- ∆H = ∆E-Q
- ∆H = ∆E+q
- ∆H = ∆E+P∆V
D
