Endothermic and Exothermic Chemical Reactions and Rate of Reactions

In an exothermic reaction, where is thermal energy located in the chemical equation?

• On the reactants' side

• On the products' side

• In the middle of the equation

• It does not appear in the equation

What happens to energy during an endothermic reaction?

• It is released to the surroundings

• It is absorbed from the surroundings

• It is conserved within the products

• It remains unchanged

Tags

NGSS.HS-PS1-4

In a cold pack, what happens to energy during the chemical reaction?

• It is released to the surroundings

• It is absorbed from the surroundings

• It is created by the reaction

• It is destroyed by the reaction

Tags

NGSS.HS-PS1-4

In an exothermic reaction, why is thermal energy released?

• The reactants have higher energy than the products

• The products require more energy to form

• Energy is stored in the reactants only

• The reaction occurs at a very high temperature

Tags

NGSS.HS-PS1-4

Temperature changes are noticeable in some reactions but not others because:

• Some reactions are exothermic or endothermic.

• All reactions release the same amount of energy.

• Temperature is not a factor in chemical reactions.

• Reactions occur at the same rate.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-5

Which statement about chemical reactions and temperature is correct?

• Only exothermic reactions affect temperature

• The type and amount of energy involved varies by reaction

• Endothermic reactions do not release any energy

• Chemical reactions do not change temperature.

Tags

NGSS.HS-PS1-4

NGSS.HS-PS1-5

NGSS.HS-PS3-4

What factor increases the reaction rate by causing more frequent collisions between particles?

• Decreased concentration

• Increased concentration

• Lower pressure

• Smaller surface area

Tags

NGSS.HS-PS1-5

What is the effect of increasing reactant concentration on the reaction rate?

• The reaction rate increases

• The reaction rate decreases

• The reaction rate remains the same

• The reaction rate stops

Tags

NGSS.HS-PS1-5

A chemical reaction in which energy is absorbed in the form of heat is called __________________.

• synthetic

• exothermic

• combustion

• endothermic

Tags

NGSS.HS-PS1-4

Which statement is true about an exothermic reaction?

• It releases energy.

• It absorbs energy.

• It requires no activation energy.

• The energy of the products is greater than the energy of the reactants.

Tags

NGSS.HS-PS1-4