Endothermic and Exothermic Reactions

What is the role of heat in exothermic reactions?

• Heat is absorbed during the reaction.

• Heat is released as a product of the reaction.

• Heat has no effect on the reaction.

• Heat is used to initiate the reaction.

What is an endothermic reaction?

• A chemical reaction that releases heat into its surroundings, increasing the temperature.

• A chemical reaction that absorbs heat from its surroundings, resulting in a decrease in temperature.

• A reaction that occurs spontaneously without any energy change.

• A reaction that only occurs in the presence of a catalyst.

What happens to temperature during an endothermic reaction?

• The temperature increases.

• The temperature remains constant.

• The temperature decreases.

• The temperature fluctuates.

What is the law of conservation of energy in relation to chemical reactions?

• Energy can be created and destroyed during chemical reactions.

• Energy can only be created during chemical reactions.

• Energy cannot be created or destroyed, only transformed from one form to another during chemical reactions.

• Energy is lost during chemical reactions.

What is a common everyday example of an exothermic reaction?

• The heat produced when burning a candle.

• The cooling effect of melting ice.

• The absorption of heat when water evaporates.

• The heat released during the dissolution of salt in water.

What is a common everyday example of an endothermic reaction?

• The fizzing sensation when eating sherbet sweets.

• Burning wood in a fireplace.

• Mixing water with salt.

• Cooking an egg in boiling water.

What is the role of heat in endothermic reactions?

• Heat is released as a product in the reaction.

• Heat is absorbed as a reactant in the reaction.

• Heat has no effect on the reaction.

• Heat is a catalyst in the reaction.

Give an example of an exothermic reaction.

• Photosynthesis of plants

• Dissolving salt in water

• Combustion of fuels, such as burning wood or gasoline

• Melting of ice

What is the difference between heat and temperature in the context of chemical reactions?

• Heat is the energy transferred due to temperature difference, while temperature is a measure of the average kinetic energy of particles.

• Heat is the total energy of a system, while temperature is the energy of the system's particles at rest.

• Heat is a measure of how hot or cold something is, while temperature is the energy transferred between objects.

• Heat is the energy stored in a substance, while temperature is the energy lost during a chemical reaction.

How do exothermic reactions feel to the touch?

• They feel cold because they absorb heat from the surroundings.

• They feel warm or hot because they release heat to the surroundings.

• They feel neutral with no temperature change.

• They feel sticky and wet.