D1 – Qualitative and quantitative
What is qualitative?
Qualitative is represented as judgment quality of something for example colour and appearance. When checking the quality of something you don’t need to measure and weight of it, so numbers are not required to identify the substances.
What is quantitative?
Quantitative is checking the quantity of something such as the weight, mass and area to ensure to ensure accuracy of that specific substance. By doing this you would know the exact amount/ weight of the substance or equipment that you are using.
Titration:
The titration that we carried out was both qualitative and quantitative. For example when we made the standard solution for the titration we used the exact quantity of the substance and we mixed it with the exact amount of deionised water (250ml) and when we were doing the calculation to get the concentration of the standard solution we made sure to use weight of the equipment that we used.
When we were caring out the titration we added indicator in the base so that the solution would turn into different colour and when we add the acid into it we would be able to tell when the end point comes because the colour will change.
Qualitative and quantitative comparison:
I think that quantitative technique is more important than qualitative for titration because if the measurements for titration and standard solution are not accurate and precise then then it can affect all of our result and conclusion can be completely different than the one expected. Qualitative on the other hand also plays important role but not as much as quantitative because the qualitative technique is only used to determine the end point.
How I can make improvements for future:
When using qualitative and quantitative techniques in titration, for the future I can ensure that I measure the exact amount of solutions that I use for quantity and determine the quality as correct as possible by pouring the acid into the base very slowly. I can use quantitative technique to make my results accurate by ensuring that when I read the amount of acid present in the burette each time, I have my eye levelled with the line the acid it up to.
Cations and anions:
The experiment that we carried out for cations and anions was qualitative because we did not measure any of the substances that we were using. When we were testing for the powders, we were checking for the quality of the solution to recognise if it was cation or anion. We recognised the quality of the solutions by checking that the solution gives off gas, checking the appearance of the solution and also checking the colour of it for example when we were using the litmus paper we checked the colour of what it has turns into. Cations also involved the technique of quality when we had to check if the precipitate was formed in the solution or not.
Qualitative and quantitative comparison:
In cation and anions I did not use any technique that involved quantity because all was based on the quality as it was most important to determine conclusion. However to improve my accuracy of the results I can use quantitative technique by measuring the solution and powders to react them together, when drawing results to determine the different cations and anion of the substances.
How I can make improvement for future:
I can make improvements for future by repeating each experiment twice to see if I get the same result. I can also use quantitative technique as well for example I can measure the substances and solutions to improve the results, that way I can reduce the risk of adding too much powder substance in the solution and determining it wrong.
Food testing:
The experiment of the food testing was qualitative because we did not measure any of the substances that we added in the food. We used the iodine to see if it changes colour when we were testing for the starch, and we did the same with the testing of the protein for example we added biurets in the food to see if the food changes into lilac colour.
But reducing sugars was qualitative and quantitative. It was qualitative because we added benedict’s solution in the food and left it in the water bath for 5 minutes and then we compared the colour the food that it turned into, using the sliding scale. It was quantitative because we compared the colour of the multistix (after putting it into the food for 5 minutes) using the chart that had number on it.
Qualitative and quantitative comparison:
We don’t need qualitative for this experiment because even if we use it, it would not make any difference as qualitative technique is more useful for this experiment because for mostly everything you need to determine the quantity to get accurate result. However your results may not be as accurate if human error is made because for example sometimes it is hard to compare the colour of the food outcome to the chart or sliding scale.
How I can make improvement for future:
I can make improvements for future by repeating my test to see if I get the same result each time. I can also make improvement by comparing the results of test, for example the change of colour, as accurately as possible to the chart and sliding scale next time.
Qualitative or quantitative:
In my point of view I think quantitative technique is much better to judge and use for the experiments to ensure accuracy because you would know the exact amount of substances that you are using, so your results would be more accurate. And also sometimes your judgments about the quality of something can be wrong for example the comparison of the colours might not be right when you compare your results with the sliding scale or chart. Another reason quantity is good because it tells you the exact amount or measurement of something, so it does not involve any human error unlike qualitative because your judgment based on this technique might be wrong.