Exothermic and endothermic reactions quiz

What do you call a reaction that transfers energy to its surroundings?

• Electrolysis

• Exothermic

• Endothermic

Answer explanation

An exothermic reaction releases energy to its surroundings, often in the form of heat. This is the opposite of an endothermic reaction, which absorbs energy. Therefore, the correct answer is exothermic.

What happens to the temperature in endothermic reactions?

• Decreases

• Stays the same

• Increases

Answer explanation

In endothermic reactions, energy is absorbed from the surroundings, leading to a decrease in temperature. This is why the correct answer is 'Decreases'.

Which type of reaction is shown in this reaction profile diagram?

• Endothermic

• Exothermic

Answer explanation

The reaction profile diagram shows a decrease in energy as the reaction proceeds, indicating that energy is released to the surroundings. This characteristic is typical of exothermic reactions, confirming the correct choice.

Which of these uses an endothermic reaction?

• Hand warmers

• Sports injury pack

• Self-heating drinks can

Answer explanation

Sports injury packs use an endothermic reaction to absorb heat, providing a cooling effect for injuries. In contrast, hand warmers and self-heating drinks generate heat through exothermic reactions.

The energy needed to start a reaction is called the .....

• Progress of time

• Start point

• Upsidedown

• Activation energy

Answer explanation

The energy required to initiate a chemical reaction is known as activation energy. It is essential for overcoming the energy barrier for the reaction to proceed, making 'activation energy' the correct choice.

Will forming new bonds release energy or take in energy?

• Take in energy

• Release energy

Answer explanation

Forming new bonds releases energy because the process of bond formation is exothermic. When atoms bond, they achieve a more stable configuration, and the excess energy is released, making 'Release energy' the correct choice.

Exothermic or endothermic?

• Endothermic

• Exothermic

Answer explanation

The correct answer is 'Exothermic' because exothermic reactions release energy, usually in the form of heat, to the surroundings, while endothermic reactions absorb energy. This distinction is key in understanding thermodynamic processes.

Exothermic or Endothermic?

• Exothermic

• Endothermic

Answer explanation

The reaction is endothermic because it absorbs heat from the surroundings, resulting in a decrease in temperature. In contrast, exothermic reactions release heat.

What happens to the temperature in exothermic reactions?

• Decreases

• Stays the same

• Increases

Answer explanation

In exothermic reactions, energy is released in the form of heat, causing the temperature of the surroundings to increase. Therefore, the correct answer is that the temperature increases.

What piece of apparatus are the reactants in an exothermic reaction added to which helps to reduce heat loss from the reaction mixture?

• Metal can

• Polystyrene cup

• Glass beaker

• Ceramic bowl

Answer explanation

The polystyrene cup is an effective insulator, minimizing heat loss during an exothermic reaction. Unlike metal cans or glass beakers, it retains heat better, making it the ideal choice for such experiments.