In I/GCSE Chemistry, we will learn about reversible changes .

Changing the temp. of tubes containing nitrogen compounds:

• Heating --> nitrogen dioxide (NO₂) gas forms-->Colour of solution changes to dark brown
• Cooling --> nitrogen tetroxide (N₂O₄) gas forms-->Colour of solution gets paler

Refer to I/GCSE Chemistry,  Water and ice are at a dynamic equilibrium because the rate of freezing = rate of melting. They are also reversible reactions.

Controlling the _PH of shampoo protects skin and eyes.

Molecular collisions

Irreversible change- products can’t form back into the original products

E.g. methane--> (combustion) -->Carbon dioxide + water = irreversible

Reversible- when products can react to produce the original reactants e.g.  Evaporation, melting

• Depends upon conditions;

Example of RR

1. Heating ice--> liquid
2. Water cools to below 0 degrees Celsius
3. Ice reforms

When it comes to I/GCSE Chemistry, 

Forwards reaction= reactants make more products

Backwards reaction= products make more reactants

Temperature and concentration affects direction of change:

• When the concentration of REACTANTS is higher, it is more likely for the reactants to collide (as there are more of them), and produce lots of products. Thus the FORWARDS reaction is more likely.

• When the concentration of PRODUCTS is higher, it is more likely that the products will collide with each other and decompose to produce lots of the original reactants. Thus the BACKWARDS reaction is more likely.

• When heat is added to the reactants, they have an advantage and will thus . This is the forwards reaction.

• When heat is added to the products, the products have the advantage and will thus produce reactants at a higher rate than the reactants are producing the products at. This is the backwards reaction.

You got it now!

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