24. Identify a source of error for the experimental design of the cobalt(II)chloride system
In the experiment, there were three test tubes.
All of them contained cobalt(II)chloride.
Test tube 1 was the constant, therefore, did not change throughout the experiment.
Test tube 2, water was added to see how that affects equilibrium change (the color changed from blue to pink)
Then later, the same test tube was placed in a warm water bath (changing temperature) and the color changed from pink to blue and equilibrium shifted.
Test tube 3, added silver nitrate to decrease the concentration of the chloride ions (a precipitate formed) and the color changed from blue to pink.
One potential source of error in the experimental design of the cobalt(II)chloride system could be inconsistent measurement of the quantities of cobalt(II)chloride, water, and silver nitrate being added to the test tubes. This can lead to variations in the initial concentrations of the substances, which can affect the equilibrium and the observed color changes.
To minimize this error, it is important to use precise measuring instruments such as calibrated pipettes or burettes to accurately measure the volumes of the substances being added. Additionally, it is crucial to follow the procedure carefully and ensure that each test tube receives the correct amount of reagents.
Another source of error could be contamination of the test tubes. If any residual substances from previous experiments are present in the test tubes, they could react with the cobalt(II)chloride or the added reagents and affect the observed color changes. To prevent this, it is important to clean the test tubes thoroughly before each experiment and ensure that they are completely dry before adding the substances.
Lastly, the temperature control of the warm water bath can introduce errors if it is not accurately maintained. Fluctuating temperatures or variations across different test tubes can lead to inconsistent results. To minimize this error, it is recommended to use a temperature-controlled water bath with a reliable thermometer to monitor and maintain the desired temperature throughout the experiment.
By addressing these potential sources of error and maintaining careful and consistent experimental procedures, the reliability and accuracy of the results for the cobalt(II)chloride system can be improved.