rate and extent of chemical change

• equilibrium is when a reversable reaction occurs in an apparatus which prevents the escape of reactants and products (a closed system)
• dynamic equilibrium is reached when the forward reaction and reverse reactions occur at exactly the same rate
• La Chatelier's Principle -

  • If a system is at equilbrium and change is made to any of the conditions, the system responds to counteract the change
• in reversable reactions, the reaction will be exothermic in one direction and endothermic in the other
• if the temperature is increased, the equilibrium will shift towards the direction in which the reaction is endothermic (to reduce the temperature)
• If the pressure is increased, the equilibrium will shift to the side with fewer gaseous molecules (moles)
• Test for chlorine -

  • damp litmus paper bleaches
• Test for oxygen -

  • glowing splint relights
• Test for Carbon Dioxide -

  • lime water turns cloudy
• test for Hydrogen -

  • lit splint squeaky pop
• increasing the temperature increases the rate of reaction as the particles move faster, and collide more frequently
• Increasing the concentration or pressure increases the rate of reaction as there are more particles in a smaller space
• Increasing the surface area increases the rate of reaction as there are more places for particles to collide
• Using a catalyst increases the rate of reaction as it decreases the activation energy, and provides an alternative reaction pathway