Unit 4 – scientific practical techniques
D1 – Evaluate the quantitative and qualitative analytical techniques used, suggesting
improvements for future investigations
In the qualitative techniques used there were errors and things that could have been changed to
achieve the most accurate results possible.
In the benedict’s test an error that occurred was the water wasn’t boiling in the beaker no
matter how long left over the Bunsen burner. This didn’t stop the experiment being carried out and
so the test tubes were placed into the hot water, it took longer than expected for colour change to
start happening. And so, if the results were recorded slightly earlier due to colour change being
slower then the results could be incorrect as they don’t fully show the colour change that should
have occurred. A way to reduce this error is by using a heating mantle as they are a lot more reliable
and heat up a lot quicker and hotter than a Bunsen burner. This means when the experiment is next
carried out, the water would be hot enough to accurately collect the correct results.
In the anion tests the same spatula was used to put each different compound into the test
tubes. This meant that some residue from the previous compound could be mixed with the next
compound when placing into the test tube. By these compounds mixing together it’s no longer pure
and is a mixed compound. This could easily show incorrect results as the two different compounds
could be giving off different reactions or they could be creating a new reaction. And so, to reduce
this error and make the experiment as accurate as possible for next time, a clean spatula should be
used for each compound. This limits any of the compounds mixing together and has the correct
reactions taking place.
…………………………………………………………………………………………………………………………………………………….
Thank you for previewing the example, feel free to buy the singular task, or the Unit 4 bundle xxx
D1 – Evaluate the quantitative and qualitative analytical techniques used, suggesting
improvements for future investigations
In the qualitative techniques used there were errors and things that could have been changed to
achieve the most accurate results possible.
In the benedict’s test an error that occurred was the water wasn’t boiling in the beaker no
matter how long left over the Bunsen burner. This didn’t stop the experiment being carried out and
so the test tubes were placed into the hot water, it took longer than expected for colour change to
start happening. And so, if the results were recorded slightly earlier due to colour change being
slower then the results could be incorrect as they don’t fully show the colour change that should
have occurred. A way to reduce this error is by using a heating mantle as they are a lot more reliable
and heat up a lot quicker and hotter than a Bunsen burner. This means when the experiment is next
carried out, the water would be hot enough to accurately collect the correct results.
In the anion tests the same spatula was used to put each different compound into the test
tubes. This meant that some residue from the previous compound could be mixed with the next
compound when placing into the test tube. By these compounds mixing together it’s no longer pure
and is a mixed compound. This could easily show incorrect results as the two different compounds
could be giving off different reactions or they could be creating a new reaction. And so, to reduce
this error and make the experiment as accurate as possible for next time, a clean spatula should be
used for each compound. This limits any of the compounds mixing together and has the correct
reactions taking place.
…………………………………………………………………………………………………………………………………………………….
Thank you for previewing the example, feel free to buy the singular task, or the Unit 4 bundle xxx
