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Energy in Chemical Reactions

Explore endothermic and exothermic reactions, activation energy, and factors affecting reaction rates.

Grade 9 Science ChemistryEnergy in Reactions
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Includes

Multiple ChoiceFill in the BlanksShort AnswerTrue / FalseCustom

Standards

HS-PS1-4HS-PS1-5

Topics

chemistryenergyreactionsexothermicendothermic
7 sections · Free to use · Printable
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Energy in Chemical Reactions

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Date:

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Read each question carefully and provide your best answer. For multiple choice questions, circle the correct option.

1. Which type of reaction releases energy into the surroundings, often leading to a temperature increase?

a

Endothermic

b

Exothermic

c

Isothermal

d

Adiabatic

2. What is the minimum amount of energy required to initiate a chemical reaction?

a

Heat of reaction

b

Activation energy

c

Bond energy

d

Kinetic energy

1. In an endothermic reaction, energy is   from the surroundings, causing the temperature to  .

2. Catalysts work by lowering the   energy of a reaction, thereby increasing the reaction  .

1. Describe the difference between an exothermic and an endothermic reaction in terms of energy flow and temperature change.

2. Explain how increasing the surface area of reactants can affect the rate of a chemical reaction.

1. All chemical reactions require an input of energy to start.

T

True

F

False

2. Increasing the concentration of reactants generally slows down a chemical reaction.

T

True

F

False

Examine the energy diagram below and answer the questions that follow.

Energy Reaction Progress Reactants Products Activation Energy ΔH

1. Is this an exothermic or endothermic reaction? Justify your answer based on the diagram.

2. Label the activation energy (Ea) and the enthalpy change (ΔH) on the diagram above.

(Note: The diagram already includes labels for Activation Energy and ΔH for reference. Your task is to identify and understand them.)