C11.9 Energy Changes I

Typically Chemical Reactions are:

• Irreversible

• Reversible

Physical reactions make something new

• True

• False

In a chemical reaction​ (a)   turn into ​ (b)   .

• reactants
• products
• elements, compounds
• substances, mixtures
• ingredients, outcomes

Chemical or physical reaction

Groups:

(a) Chemical

,

(b) Physical

• Diffusion

• Photosynthesis

• Precipitation

• Digestion

• Chopping wood

• Respiration

• Combustion

• Displacement

• Dissolving

• Neutralisation

Exothermic or endothermic process?

Groups:

(a) Exothermic

,

(b) Endothermic

,

(c) Either

• Displacement

• Neutralisation

• Photosynthesis

• Chopping wood

• Combustion

• Precipitation

• Respiration

• Dissolving

• Melting ice

• Thermal decomposition

Describe the changes in an endothermic and exothermic reaction

Groups:

(a) Endothermic

,

(b) Exothermic

• Temperature of the surroundings rises

• Heat energy is absorbed from the surroundings

• Chemical energy changes to heat energy

• Heat/Light energy is stored in chemical bonds

• Temperature of the surrounding falls.

• Heat energy is transferred to the surroundings