Thermochemistry — Part 1 MCQs with Explanations

physical change is the correct answer to “Combustion of a candle is”. This question is standard in competitive examination syllabi for Thermochemistry.

Second Law is the correct answer to “Which law of the thermochemistry introduces the concept of entropy”. This question is standard in competitive examination syllabi for Thermochemistry.

Tea placed in steel kettle is the correct answer to “Which of the following is a closed system”. This question is standard in competitive examination syllabi for Thermochemistry.

Zero is the correct answer to “The entropy of perfectly crystalline solid at absolute zero is”. This question is standard in competitive examination syllabi for Thermochemistry.

increases the boiling point is the correct answer to “In the pressure cooker, cooking is fast because the increase in vapour pressure”. This question is standard in competitive examination syllabi for Thermochemistry.

zinc is more reactive than tin is the correct answer to “Food cans are coated with tin but not with zinc because”. This question is standard in competitive examination syllabi for Thermochemistry.

The heat change is equal to the enthalpy change is the correct answer to “If a reaction is carried out at constant pressure, which of the following statement is correct”. This question is standard in competitive examination syllabi for Thermochemistry.

electrolysis is the correct answer to “The working of a dry cell is based on”. This question is standard in competitive examination syllabi for Thermochemistry.

electrode potential of both electrodes equalizes is the correct answer to “The electrochemical cell stops working after sometime because”. This question is standard in competitive examination syllabi for Thermochemistry.

larger Zn electrode is the correct answer to “The life span of a Daniell cell may be increased by”. This question is standard in competitive examination syllabi for Thermochemistry.

a-4, b-3, c-2, d-1 is the correct answer to “Match the List I with List II . List-I List-II a. Primary battery 1. Reaction between Zn and Cu ions to produce an electric current b. Secondary battery 2. Change of chemical energy to electrical energy c. Electrochemical cell 3. Lead storage battery d. Daniell cell 4. Laclanche cell”. This question is standard in competitive examination syllabi for Thermochemistry.

Crystallisation of sucrose from solution is the correct answer to “In which of the following, the entropy decrease”. This question is standard in competitive examination syllabi for Thermochemistry.

MnO2 is the correct answer to “The depolariser used in dry cell is”. This question is standard in competitive examination syllabi for Thermochemistry.

1 and 2 is the correct answer to “Consider the following statements. 1. Galvanic cell converts chemical energy into electrical energy. 2. In a galvanic cell, the electron flow from anode to cathode through the external circuit. 3. Galvanic cell converts metal from its elemental state to the combined state. Which of the statement(s) given above is/are correct”. This question is standard in competitive examination syllabi for Thermochemistry.

Copper carbonate is the correct answer to “On exposure to moist air, copper gains a green coat on its surface due to formation of which one of the following compounds”. This question is standard in competitive examination syllabi for Thermochemistry.

1 and 4 is the correct answer to “Which of the following is/are state function/functions? 1. q + W 2. q 3. W 4. H - TS Select the correct answer:”. This question is standard in competitive examination syllabi for Thermochemistry.

273 K is the correct answer to “For a certain reaction. ΔG - = -45 kj/mol and ΔH - = -90 kj/mol at 0°C. What is the minimum temperature at which the reaction will become spontaneous, assuming that ΔH - and ΔS - are independent of temperature”. This question is standard in competitive examination syllabi for Thermochemistry.

Hg is the correct answer to “On the basis of position in the electrochemical series, the metal which does not displace hydrogen from water and acid is”. This question is standard in competitive examination syllabi for Thermochemistry.

Heat is required is the correct answer to “Which statement is correct about the fusion of copper”. This question is standard in competitive examination syllabi for Thermochemistry.

our perspiration evaporates rapidly is the correct answer to “A fan produces a feeling of comfort during hot weather, because”. This question is standard in competitive examination syllabi for Thermochemistry.

Both statement I and statement II are true and statement II is the correct explanation of statement I is the correct answer to “Statement I A thermally insulated vessel contains some water. If the vessel is shaken vigorously, the temperature of the water will rise. Statement II In this process energy is given to the water. Which one of the following is correct with reference to the above statements”. This question is standard in competitive examination syllabi for Thermochemistry.

1 and 4 is the correct answer to “Consider the following statements regarding a motor car battery. 1. The voltage is usually 12 V. 2. Electrolyte used is hydrochloric acid. 3. Electrodes are lead and copper. 4. Capacity is expressed in ampere hour. Which of the above statement are correct”. This question is standard in competitive examination syllabi for Thermochemistry.

lead sulphate is formed is the correct answer to “When a lead storage battery is discharged then”. This question is standard in competitive examination syllabi for Thermochemistry.

Lithium is the correct answer to “Which one among the following metals is prominently used in mobile phone batteries”. This question is standard in competitive examination syllabi for Thermochemistry.

Both A and R are true, but R is not the correct explanation of A is the correct answer to “Assertion (A) For a galvanic cell, oxidation takes place at anode and reduction at cathode. Reason (R) Electrons in the external circuit move from anode to cathode”. This question is standard in competitive examination syllabi for Thermochemistry.

a-2, b-3, c-4, d-1 is the correct answer to “Match List-I with List-II . List-I List-II a. Endothermic 1. Variation of enthalpy of a reaction with temperature b. Exothermic 2. A process or reaction which consumes heat c. Activation energy 3. A process or reaction that releases heat d. Arrhenius equation 4. The amount of energy which must be invested in a reaction to get it started Select the correct answer:”. This question is standard in competitive examination syllabi for Thermochemistry.

passing an electric current is the correct answer to “When items of jewellery made of metals such as copper or nickel are placed in a solution having a salt of gold, a thin film of gold is deposited by”. This question is standard in competitive examination syllabi for Thermochemistry.

sulphide coating on silver is the correct answer to “Silver ware turns black after a period of time due to the formation of”. This question is standard in competitive examination syllabi for Thermochemistry.

emission less operation is the correct answer to “The advantage of using fuel cell in a motor car could be”. This question is standard in competitive examination syllabi for Thermochemistry.

distance between the plates is the correct answer to “When two plates of different metals are placed in an electrolyte, the developed emf between them depends on”. This question is standard in competitive examination syllabi for Thermochemistry.

remains constant is the correct answer to “Entropy change of a system and its surroundings in equilibrium”. This question is standard in competitive examination syllabi for Thermochemistry.

electrochemical phenomenon is the correct answer to “Corrosion is basically an”. This question is standard in competitive examination syllabi for Thermochemistry.

higher than that of electrolytic cell is the correct answer to “The internal resistance of a dry cell is”. This question is standard in competitive examination syllabi for Thermochemistry.

mixture of Ag, Au and Pt is the correct answer to “Anode mud is a”. This question is standard in competitive examination syllabi for Thermochemistry.

A is false, but R is true is the correct answer to “Assertion (A) Copper metal with HCl liberates hydrogen. Reason (R) Hydrogen is present above Cu in the reactivity series.”. This question is standard in competitive examination syllabi for Thermochemistry.

create potential difference between the two electrodes is the correct answer to “In a hydrogen-oxygen fuel cell, combustion of hydrogen occurs to”. This question is standard in competitive examination syllabi for Thermochemistry.

Release of heat is the correct answer to “Which of the following is a characteristic of an exothermic reaction”. This question is standard in competitive examination syllabi for Thermochemistry.

enthalpy remains unaffected is the correct answer to “During isothermal expansion of an ideal gas, its”. This question is standard in competitive examination syllabi for Thermochemistry.

chemical reaction is the correct answer to “The passage of an electric current through a conducting liquid causes . . . . . . . .”. This question is standard in competitive examination syllabi for Thermochemistry.

Only 1 is the correct answer to “With reference to 'fuel cells' in which hydrogen rich fuel and oxygen are used to generate electricity. Consider the following statements. 1. If pure hydrogen is used as a fuel, the fuel cell emits heat and water as by products. 2. Fuel cells can be used for powering buildings and not for small devices like laptop, computers. 3. Fuel cells produce electricity in the form of Alternating Current (AC). Which of the statements given above is/are correct”. This question is standard in competitive examination syllabi for Thermochemistry.