Investigating the effect of concentration changes on rate of Reaction
Outline
When Hydrochloric acid reacts with Sodium thiosulphate, a fine suspension of sulphur slowly forms.
2HCl + Na S O 2NaCl + S + SO + H O
When the concentration of hydrochloric acid changes the rate also changes. To measure the effect of concentration on rate , we need to carry out an experiment, in which the rate would be measured by finding out how quickly the sulphur forms.
These factors affect rate in this experiment:
. Concentration
2. Pressure
3. Temperature
4. Catalysts
(Surface area would have no effect as it only has an effect on solids.)
The concentration is what we are going to change, therefore it is the independent variable. We are going to change the concentration by using different volumes of Hydrochloric acid and water. The rate is what is going to change due to the dependent variable. This is going to be measured by seeing how long it takes for the sulphur to form and block out a cross, which is beneath the transparent apparatus, from our view. The remaining factors mentioned above will stay the same, i.e. They will be the controlled variables. Therefore, the temperature will be kept the same, the pressure will be kept the same, the same volume of hydrochloric acid will be used every time, the same volume of sodium thiosulphate will be used every time, and no catalyst will be used.
Outline
When Hydrochloric acid reacts with Sodium thiosulphate, a fine suspension of sulphur slowly forms.
2HCl + Na S O 2NaCl + S + SO + H O
When the concentration of hydrochloric acid changes the rate also changes. To measure the effect of concentration on rate , we need to carry out an experiment, in which the rate would be measured by finding out how quickly the sulphur forms.
These factors affect rate in this experiment:
. Concentration
2. Pressure
3. Temperature
4. Catalysts
(Surface area would have no effect as it only has an effect on solids.)
The concentration is what we are going to change, therefore it is the independent variable. We are going to change the concentration by using different volumes of Hydrochloric acid and water. The rate is what is going to change due to the dependent variable. This is going to be measured by seeing how long it takes for the sulphur to form and block out a cross, which is beneath the transparent apparatus, from our view. The remaining factors mentioned above will stay the same, i.e. They will be the controlled variables. Therefore, the temperature will be kept the same, the pressure will be kept the same, the same volume of hydrochloric acid will be used every time, the same volume of sodium thiosulphate will be used every time, and no catalyst will be used.
