 Increasing the concentration of a reactant substance will increase the rate of reaction. This is because more collisions will occur, and therefore more successful collisions.

 Eg – we used HCl of 2M the other day and it would cause a faster reaction than 1M because it has a higher concentration.

 If surface area is increased – more particles are exposed for collisions to occur.

 If surface area is increased – more particles are exposed for collisions to occur. The rate of reaction will increase as there are more collisions, therefore more successful collisions.

 EG – Calcium carbonate powder reacted much faster in HCl than Calcium carbonate chips. This is because the powder has a larger surface area.

 When temperature increases, particles move faster and collide more often.

 The particles also have more energy to collide with = more products.

 A catalyst is a chemical or substance that is added to a reaction to speed it up.

 The catalyst does not change the products formed and doesn’t get used up in the reaction (so can be used again).

 A catalyst is a chemical or substance that is added to a reaction to speed it up.  The catalyst does not change the products formed and doesn’t get used up in the reaction (so can be used again).  The reaction rate increases because the catalyst lowers the activation energy needed for the reaction to occur.

 Set up two test tubes in a holder  Pour same amounts of hydrogen peroxide into them (about 2cm)  In one test tube, put a small amount of manganese dioxide  Light a splint and shake it out (so it’s glowing)  Place it over the test tube WITHOUT the manganese dioxide – what happens?  Now, repeat it, and place the glowing splint over the other test tube – what happens?

 Hydrogen peroxide decomposes slowly to form water and oxygen gas.  If a catalyst (manganese dioxide) is added, a rapid supply of oxygen gas is produced

 Hydrogen peroxide decomposes slowly to form water and oxygen gas.  If a catalyst (manganese dioxide) is added, a rapid supply of oxygen gas is produced  Hydrogen peroxide  water + oxygen

 Hydrogen peroxide decomposes slowly to form water and oxygen gas.  If a catalyst (manganese dioxide) is added, a rapid supply of oxygen gas is produced  Hydrogen peroxide  water + oxygen  H 2 O 2  H 2 O + O 2

 Hydrogen peroxide decomposes slowly to form water and oxygen gas.  If a catalyst (manganese dioxide) is added, a rapid supply of oxygen gas is produced  Hydrogen peroxide  water + oxygen  H 2 O 2  H 2 O + O 2  2H 2 O 2  2H 2 O + O 2