rates of reaction

• The 5 ways to speed up a chemical reaction 


  1.pressure

  2.concentration

  3.temprature

  4.surface area

  5.a catalyst
• why does adding a catalyst speed up the rate of reactions


  catalysts speed up reactions by lowering the activation energy required for a reaction to occur.

  they do this by giving an alternative route that requires less energy
• why does increasing temperate increase the rate of reaction 


  when the reactants are heated , the energy of the molecules increase. This means that more molecules are moving faster and hitting each other with more energy.
• why does increasing pressure of a gas speed up a reaction


  There are more reactant particles for a given volume . This means there will be more collisions so the reaction rate increases.
• why does surface area increase the rate of reaction


  if the surface area is increased it means there are more particles exposed to the reactant. this means there is a grater chance of particles colliding.
• why does concentration increase the rate of reaction 


  if the concentration of reactants are increased , there are more reactant particles moving together, increasing the amount of collisions.
• what is the collision theory 


  collision theory states that for particles to react, they have to collide with sufficient energy and at the right direction.
• what is activation energy 


  the minimum amount of energy that particles require to react together
• what is a rate of reaction 


  the rate of reaction refers to the speed at which the reactants must possess in order to undergo a specified reaction
• variables for the colour change practice

  control - concentration/ volume of sodium thiosulfate

  independent - temperature of acid

  dependant - time taken for 'x' to disappear
• variables for the production of gas practical 


  control- volume of hydrochloric acid

  independent - concentration of hydrochloric acid

  dependent- volume of gas produced
• chemical reaction for production of gas practice 


  calcium carbonate + hydrochloric acid --> calcium chloride+ water+ carbon dioxide
• chemical reaction for colour change practice 


  sodium thiosulfate + hydrochloric acid --> sodium chloride + water + sulfur+ sulfur dioxide
• how many reactants and products in the colour change practical


  there are 2 reactants and 4 products
• how many reactants and products in the production of gas practical 


  there are 2 reactants and 3 products
• In the colour change practice, what was the product that irritated the lungs

  sulfur dioxide
• during the colour change practical, what was the product that makes it cloudy

  sulfur
• how many times should you repeat both practicals 


  3 times so you can find the mean
• formular to find the gradient of a line ?


  gradient = change in y / change in x
• what is the formular for calculating the rate of a chemical reaction 


  rate = mass of product produced or loss/ time taken