Equilibria

• Increase in temperature -> shifts to endothermic side • Increase in pressure -> shifts to side with least gas moles • Increase in reactant -> shifts to other side

Aluminium oxide (different) silica (cracking)

• Speeds up the rate of reaction • By providing an alternative pathway • Which lowers the activation energy • Does not get used up in the reaction

This is a reaction which can go both ways as the products can react to produce the original reactants

Reduces the yield of product, so conditions must be chosen to shift the equilibrium towards the prodcuts

• A reversible reaction where the: • rate of the forward reaction = rate of the reverse reaction • conentration of reactants + products is constant • Happens in a closed system (so that no molecule may enter/leave)

• Heating copper sulphate crystals • heating ammonium chloride • colbalt chloride

Steps: * Place 1 cm depth of hydrated copper sulphate in a boiling tube * Heat till copper sulphate turns white (forward reaction) * allow tube to cool for a few minutes * add water with a pipette * Copper sulphate should turn blue (backward reaction) CuSO4.5H2O -> CuSO4 + 5H2O

• Place 1cm of ammonium chloride in a test tube and put mineral wool to prevent gases from escaping • Heat the ammonium chloride at the base at the base of the tube for a couple of minutes • decomposes into 2 colourless gases so white solid disappears and reappears further up as the gases cool. NH4Cl -> NH3 + HCl