Reaction Rates

AimTo find out if temperature affects the speed of a reaction Apparatus dilute hydrochloric acid piece of zinc hot water

1.Two test tubes were ½ filled with acid 2.One tube was heated up in a beaker of hot water 3.A piece of zinc was added to each and the reaction was observed Method Results The zinc reacted faster in the hot acid

The concentration of an acid tells us about “how much” is dissolved in the solution It is measured in units called moles per litre or mol/litre (sometimes a capital M is used) The bigger the number the greater the concentration 4 mol/litre is four times more concentrated than 1 mol/litre

AimTo find out if concentration affects reaction speed Apparatus 1 mol/l acid + 2 pieces of magnesium 4 mol/l acid + 2 pieces of magnesium then colourless gas burning wooden splint

Method1.One tube was ¼ filled with 1 mol/litre hydrochloric acid and the other 4 mol/litre 2.Two pieces of magnesium were added to each and the tubes were observed to see what happened 3.Any gas given off was collected and tested with a lighted wooden splint ResultsThe more concentrated acid reacted fastest The colourless gas burned with a “pop” – it was hydrogen

AimTo find out if particle size affects reaction speed Apparatus cold water spatula with powdered iron iron nail held in tongs

Results The powdered iron reacted faster than the nail. The smaller the size of the particles the faster the chemical reaction.

reaction rate (speed) can be increased by increasing the temperature decreasing the particle size increasing the concentration

..\..\..\..\Spotlight Science\Spotlight Videos\Science in Action Videos\dvd 2\Play Disk.lnk

Fe O O O O O O When sprinkled in to the bunsen flame the iron reacted with oxygen in air to form iron oxide Iron oxide is a compound because it has more than one kind of atom in it W A compound is a substance made of atoms of different kinds joined together

the 1 st word gives the name of the 1 st element the 2 nd word changes its ending to give the other element

iron and oxygen sodium and chlorine copper and sulphur