What does it mean, when a reaction is exothermic?
Correct answer: C. Heat is transferred from the system to the surrounding
- A. Energy content of product is more
- B. Energy content of reactant is less
- C. Heat is transferred from the system to the surrounding
- D. Heat is transferred from the surrounding to the system
Explanation
An exothermic reaction is a chemical reaction that releases energy in the form of heat. This means that the energy content of the products is less than the energy content of the reactants. The heat is transferred from the system to the surroundings, which means that the temperature of the surroundings increases. So the answer is heat is transferred from the system to the surrounding. Here is an example of an exothermic reaction: Burning wood: When wood burns, it releases heat and light. The heat is transferred from the system (the wood) to the surroundings (the air). Here is another example of an exothermic reaction: Neutralization reaction: When an acid and a base react, they produce a salt and water. This reaction releases heat, which can be felt as a warming sensation.
Last updated
About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
Practise Thermochemistry and Energetics of Chemical Reactions
728 free Thermochemistry and Energetics of Chemical Reactions MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1/2 H2(g) ➞ H(g) ∆H = 218 kJ mol-1.In this reaction, ∆H will be called:
1 Kcal is equal to:
2P(s) 3CI2(g) 2PCI3 ∆H= 151.8 kJ PCl3+ CI2(g) , PCI5(g); ∆H = -32.8 kJFrom the following data, the heat of formation of PCI5 comes out to be :
5 calories are equivalent to _ Joule.
5 mole of an ideal gas expand reversibly from a volume of 8 dm3 to 80 dm3 at a temperature of 27°C. Calculate the change in entropy.