what I need to learn

particles have to collide with enough energy for the collision to be successful

the rate of reaction depends on

• temperature
• concentration
• pressure
• surface area
• catalyst

increase in temperature so particles move faster so they collide more frequently and have more energy so more collisions have enough energy to make the reaction happen

enzymes provide an alternative reaction pathway

colour change experiment- results are subjective and you cant plot a graph from the results

volume of gas given off experiment- if reaction too vigorus it can blow the plunger off the syringe

magnesium and hcl remember to plug the top with cotton wool

sodium thiosulfate and hcl make a yellow precipitate of sulfur

when the foward reaction is going at the same rate as the backwards reaction they have reached equilibrium

equilibrium is only reached in a closed system

the position of equilibrium relies on 

• temperature
• pressure
• concentration

le chatelier's principle- if you change the conditions of a reversible reaction at equilibrium, the system will counteract that change

decrease temp- move to exothermic side and you have more products there

increase pressure- moves in direction of fewer molecules

concentration- if you increae the reactants the system will increase the products