What’s the end point?

National 4 & 5 Nat 4/5 Chemical changes & structure Acids & alkalis / Strong and weak acids Neutralisation reactions Nat 4 = ?? , use of neutralisation reactions & analysis of the environment. Nat 5 = physical & chemical properties used to differentiate between strong & weak acids related to the degree of dissociation, titration used as an analytical technique.

Neutralisation & Conductivity Any change in the H+ ion concentration which makes a solution neutral, brings the pH to 7. Conductivity This depends on the mobility (type) and concentration (number) of ions present. End point Can be judged when the conductivity is at its lowest or constant value. Remember Although the H+ ions have been removed there maybe other ions present in the solution.

Practical activities In your pairs follow the What’s the end point instruction sheet for experiment.

Some metals, their oxides or carbonates & acids Other applications Precipitation reactions Some metals, their oxides or carbonates & acids