How can use titrations to work out the concentration of a chemical Starter: HCl + NaOH NaCl +H2O H+ + OH -  H2O What do these reactions show? What conditions are necessary for this to occur? Look at freezaray

Glossary Titration – a method for measuring the volumes of two solutions that react together. Alkali – A soluble base with a pH less than 7.

Titrations -strong acid + strong alkali = neutralise & form a salt -But ONLY if they are in exactly the right quantities. Otherwise, one (acid or alkali) will be in excess Quick Check: -If there is more acid than alkali to start with in a neutralisation reaction, what will happen? The final solution will be acidic

This is shown using an indicator. Titration A way to measure volumes precisely End Point The point at which the acid and alkali have reacted completely. This is shown using an indicator.

Concentration = no. of moles volume Learn this formula triangle! n c v number of moles concentration (in mol dm-3) volume (in dm3)

The Method V:\Science\Teaching resource store\Freezeray Chem Simulations\titrations[1].swfhttp://www.mhhe.com/physsci/chemistry/animations/chang_7e_esp/crm3s5_5.swf

Calculations Follow the example. Read the instructions and use them to answer the first half of the worksheet. Print out

Reactions that aren’t a 1:1 ratio