HC Energy Changes in Chemical Reactions

If a substance evaporates, is that endothermic or exothermic?

• exothermic

• endothermic

Energy in exothermic reactions is... (reaction is the system)

• released - it would make us feel cold

• absorbed - it would us feel cold

• released - it would make us feel warm

• absorbed - it would make us feel warm

Tags

NGSS.HS-PS1-4

During an endothermic reaction (reaction is system) in a beaker if we are part of the surroundings and touched the beaker, it would feel _______.

• Warm

• Cold

Tags

NGSS.HS-PS3-4

Which of the following process is exothermic?

• Candle was melting

• A puddle evaporating

• Dry ice (solid carbon dioxide) subliming to form gaseous carbon dioxide

• Water freezing to form ice

Tags

NGSS.HS-PS1-4

If you go to the beach on a hot sunny day, the sand may feel hot. If you then stand in the ocean, the water may still feel cold. (You are the system - are you absorbing or releasing?!) These are examples of....

• an endothermic process followed by an exothermic process

• an exothermic process followed by an endothermic process

• endothermic processes only

• exothermic processes only

Tags

NGSS.HS-PS3-4

A student mixed two chemicals in water to allow them to react. The temperature of the water before the reaction was 25 ° C. The temperature of the water after the reaction was 18° C. Which of the following is true?

• It is an exothermic reaction

• It is an endothermic reaction

Tags

NGSS.HS-PS1-4

NGSS.HS-PS3-4

When bonds are broken, is that an endothermic or exothermic process?

• Endothermic

• Exothermic

Tags

NGSS.HS-PS1-4

When bonds are formed, is that an endothermic or exothermic process?

• Endothermic

• Exothermic

Tags

NGSS.HS-PS1-4

The minimum amount of energy needed for colliding particles to react is called the

• Chemical Energy

• Kinetic Energy

• Activation Energy

• Potential Energy

Which letter corresponds to the energy of the reactants?

• A
• B
• C
• D

Tags

NGSS.HS-PS1-4