Scientific information
Reactivity series.
The Reactivity Series is an arrangement of metals in an order that shows how well they react with other substances. Metals vary widely in their ability to react. Sodium and magnesium react very violently. If sodium is dropped into water it fizzes and pops, giving off hydrogen. Sodium burns in oxygen to produce a dazzlingly bright flame. The position of a metal in the reactivity series tells chemists how it will behave in the presence of other metals. Sodium can be put at the top of the reactivity series, with copper nearer the bottom. Since sodium reacts violently with water, they would not consider using it for holding water.
Hydrochloric acid.
The appearance of Hydrochloric acid is a clear colourless or slightly yellow liquid with strong odour. Concentrated acid is fuming. Its melting point is -25 C and its boiling point is 109 C. It is quite stable but you must avoid heat and flames. It is incompatible with most common metals and metal oxides. For safety you must wear safety glasses and have effective ventilation.
Method:
I shall heat the sodiumthiosulphate in a water bath before I begin the experiment. The water bath will help to keep the temperature constant. The sodiumthiosulphate will have to be placed into two test tubes while in the water bath to hold them properly. I will add the sodiumthiosulphate to the hydrochloric acid in a conical flask, and watch the reaction. Underneath the flask will be a cross, marked on a waterproof mat. This will help tell when the reaction is over. A solid form of sulphur is left in a solution of water, and this makes it a cloudy yellow colour. When I cannot see the cross through the solution I will know that the reaction is over. I will time the reaction with a stopwatch.
Plan
Scientific information
Reactivity series.
The Reactivity Series is an arrangement of metals in an order that shows how well they react with other substances. Metals vary widely in their ability to react. Sodium and magnesium react very violently. If sodium is dropped into water it fizzes and pops, giving off hydrogen. Sodium burns in oxygen to produce a dazzlingly bright flame. The position of a metal in the reactivity series tells chemists how it will behave in the presence of other metals. Sodium can be put at the top of the reactivity series, with copper nearer the bottom. Since sodium reacts violently with water, they would not consider using it for holding water.
Hydrochloric acid.
The appearance of Hydrochloric acid is a clear colourless or slightly yellow liquid with strong odour. Concentrated acid is fuming. Its melting point is -25 C and its boiling point is 109 C. It is quite stable but you must avoid heat and flames. It is incompatible with most common metals and metal oxides. For safety you must wear safety glasses and have effective ventilation.
Planning:
To make the experiment safe I will wear goggles when conducting the experiment. The equipment I will use is:
- Conical Flask - to hold them
- Two measuring cylinders - to measure the amounts
- Card marked with cross - to help tell when the reaction is over
- Stopwatch - to time the reaction.
- Water bath - to heat the sodiumthiosulphate and keep it at a constant temperature.
- Two test tubes - to put the sodiumthiosulphate in the water bath while heating.
I shall be using 50ml of sodiumthiosulphate and 10ml of diluted hydrochloric acid. The hydrochloric acid will be diluted 5ml acid, 5ml water.
Fair testing:
To keep this a fair test I will keep these variables the same:
Concentration of Sodiumthiosulphate: I will keep this the same because the higher the concentration of the Sodiumthiosulphate the more particles there will be reacting with each other, so speeding up the experiment which would affect my results.
Volumes of HCl and Na2S2O3: I will keep this the same because the higher the volume of the Sodiumthiosulphate and Hydrochloric acid the more particles there will be reacting with each other, so speeding up the experiment which would affect my results.
Results:
Graphs
Conclusion
Evaluation
