Exothermic and Endothermic Reactions

Give an example of an exothermic reaction.

• Photosynthesis in plants

• Dissolving ammonium nitrate in water

• Combustion of fuels, such as burning wood or gasoline

• Melting of ice

What is the role of energy in chemical reactions?

• Energy is always released during chemical reactions.

• Energy has no effect on chemical reactions.

• Energy is either absorbed or released during chemical reactions, influencing the reaction's temperature and spontaneity.

• Energy is only absorbed in endothermic reactions.

What is the significance of the energy term in a chemical equation?

• It indicates the temperature change during the reaction.

• It shows the concentration of reactants and products.

• It indicates whether the reaction is exothermic (releases energy) or endothermic (absorbs energy).

• It represents the volume of gases produced in the reaction.

What is the effect of an exothermic reaction on the surrounding environment?

• Exothermic reactions can decrease the temperature of the surrounding environment, making it feel cooler.

• Exothermic reactions have no effect on the surrounding environment.

• Exothermic reactions can increase the temperature of the surrounding environment, making it feel warmer.

• Exothermic reactions can cause the surrounding environment to become more acidic.

What happens to the temperature of the surroundings during an exothermic reaction?

• The temperature of the surroundings decreases during an exothermic reaction.

• The temperature of the surroundings remains constant during an exothermic reaction.

• The temperature of the surroundings increases during an exothermic reaction.

• The temperature of the surroundings fluctuates randomly during an exothermic reaction.

Give an example of an endothermic reaction.

• Photosynthesis in plants

• Combustion of gasoline

• Respiration in animals

• Dissolving salt in water

How can you identify an exothermic reaction in a laboratory setting?

• By observing a decrease in temperature

• By a noticeable increase in temperature or the release of heat

• By the formation of a precipitate

• By the change in color of the reactants

What is the general formula for an exothermic reaction?

• Reactants + Energy → Products (heat is absorbed)

• Reactants → Products + Energy (heat is released)

• Reactants → Products (no energy change)

• Reactants + Products → Energy (heat is released)

How can you identify an endothermic reaction in a laboratory setting?

• By a noticeable increase in temperature

• By a noticeable decrease in temperature or the absorption of heat

• By the release of gas bubbles

• By a change in color of the reactants

What happens to the temperature of the surroundings during an endothermic reaction?

• The temperature of the surroundings increases during an endothermic reaction.

• The temperature of the surroundings remains the same during an endothermic reaction.

• The temperature of the surroundings decreases during an endothermic reaction.

• The temperature of the surroundings fluctuates during an endothermic reaction.