The heat of reaction is the quantity of heat released or absorbed when the number of moles of reactants indicated by the chemical equation has completely reacted. The amount of heat energy given out or taken in during a chemical reaction is called the enthalpy change or the heat of reaction. The symbol for this is 𐤃H. The heat of reaction is usually measured in kilojoules. The heat of reaction is either negative or positive. For exothermic reactions, 𐤃H is negative. For endothermic reactions, 𐤃H is positive. The heat of a reaction was determined, either directly or calculated indirectly from the heat of combustion data, because it was thought at the time that the heat change, 𐤃H, was the sole driving force of a chemical reaction.
1. The energy released in the form of nuclear radiation in addition to heat and light during nuclear reactions is known as
- chemical energy
- nuclear energy
- heat energy
- electrical energy
Answer: (b)
2. Fireworks release energy in the form of
- heat
- sound
- light
- all of the above
Answer: (d)
3. The energy obtained from electric cells and batteries as a result of a chemical reaction is called
- chemical energy
- nuclear energy
- heat energy
- electrical energy
Answer: (a)
4. As the rain falls the potential energy changes to
- thermal energy
- chemical energy
- kinetic energy
- nuclear energy
Answer: (c)
5. The energy coming directly from magma called
- mechanical energy
- geothermal energy
- heat energy
- electrical energy
Answer: (b)
6. In the process of rubbing hands, mechanical energy is converted into
- sound energy
- electrical energy
- thermal energy
- heat energy
Answer: (c)
7. When a body vibrates, it produces
- sound
- water
- heat
- electricity
Answer: (a)
8. In the exothermic reaction, the enthalpy of reaction is always
- zero
- positive
- negative
- none of these
Answer: (c)
9. The heat required to raise the temperature of 1 mole of a substance by 1o is called
- specific heat
- molar heat capacity
- water equivalent
- specific gravity
Answer: (b)
10. The amount of heat required to raise the temperature of a body through 1oC is called its
- molar heat
- specific heat
- entropy
- thermal capacity
Answer: (b)
Recommended:
- NEET Chemistry Syllabus
- NEET Chemistry Important Topics
- NEET Chemistry MCQs
- How to Score 160 Plus in NEET Chemistry
- NEET Chemistry Weightage
- Chemistry Formulas for NEET
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