Reactants, Products, and Bond Energy

Chemical Equilibrium

Chemical Reactions Release or Absorb Energy
Endothermic and Exothermic Reactions
Vocabulary
100

What is the relation between reactants and products?

Reactants, which are raw materials or substances, undergo through chemical changes which transform these into products.


100

What do the arrows in the equation show?

The arrows in the equation show that the reaction goes in both directions.

100

______________ is the amount of energy that needs to be absorbed for a chemical reaction to start.

Activation energy

100

The prefix that means “out” is...

Exo-

100

_________________ change substances into different substances by breaking and forming chemical bonds.

Chemical reactions

200

What happens to bonds when reactants transform into products?

When reactants transform into products, bonds between atoms are broken and later new ones are formed.

200

___________ is reached when both the reactants and products are made at the same rate.

Equilibrium  

200

When new bonds are formed in the products, ______ is released.

Energy
200

The prefix that means “in” is...

Endo-
200

____________ are the substances changed during a chemical reaction.

Reactants

300

In what format are chemical reactions represented?

Chemical reactions are represented by chemical equations, which are formatted in the way that reactants are on the left side of the equation and products are on the right side.

300

True or False. Chemical equilibrium is reached when both the reactants and products are made at the same rate.

True

300

Whether a reaction releases or absorbs energy depends on __________.

a) Bond Energy

b) Energy

c) Activation Energy

Bond Energy

300

Is melting ice endothermic or exothermic?

Endothermic

300

___________ are the substances made by a chemical reactions.

Products 

400

How is bond energy and the transformation of reactants into products related?

Since the transformation of reactants into products requires bonds to be broken, a specific amount of energy is necessary to break these bonds. This energy needed is called bond energy.

400

True or False. Chemical equilibrium occurs when chemical reactions in living organisms are reversible, meaning they can move in different directions.

False. Chemical equilibrium occurs when chemical reactions in living organisms are reversible, meaning they can move in BOTH directions.

400

A girl is pushing her sled up a mountain. Once she reaches the top of the mountain, she pushes the slide a little hard and it slides down the mountain without her. Can this be an example of activation energy? If so, in what part of the text is activation energy represented?

Yes, in the part that mentions she is pushing her sled up the mountain.

400

When you burn wood, is it an exothermic change?

Yes, it is an exothermic reaction.

400

___________ is the amount of energy that will break a bond between two atoms.

Bond energy 

500

How can the energy required to break bonds be compared to the energy released after the formation of new bonds?

The same amount of energy required to break apart bonds is the same that is released after the formation of new bonds.

500

What does it mean for a reaction to be reversible in living organisms?

They can move in both directions, from reactants to products and vice versa.

500

The two types of chemical reactions are...

Endothermic and Exothermic

500

What kind of change happens when we cook food, endothermic or exothermic?

Endothermic

500

An ____________________________ releases more energy than it absorbs.

Exothermic chemical reaction  

M
e
n
u