Determination of enthalpy change of neutralisation Flashcards
1
Q
WHat is the enthalpy change of neutralisation?
A
- enthalpy change when one mole of acid and alkali react to produce 1 mol of water
2
Q
WHat is the reaction done in?
A
- polystyrene cup in a glass beaker for support
3
Q
WHy is a polysyrene cup used as a calorimiter?
A
- low specific heat capacity
4
Q
How is the acid measured?
A
- rinse measuring cylinder
- then measure 25cm3
5
Q
WHat is done with acid in cup>
A
- stir and measure temperature
- rinse second measuring cylinger then add equal volume of alkali
6
Q
What is recorded?
A
highest temp reaxched
7
Q
How is a graphm used?
A
- record temperature against time
- extrapolate the cooliung curve to the point of mixing the reactant
8
Q
When is the graph used >
A
- reaction is slow
- exact temperature rise is hard to obtain as cooling occurs at the same tome as the reaction
9
Q
WHat are the errors?
A
- heat loss/gain
- approximation of specific heat ca[acoty of solution
- neglecting specific heat capacity of calorimiter
- reaction incomplete
- assuming density of solution same as water
