Atoms have different number of shells depending on the amount of electrons it has. The innermost shell of an electron can have a maximum of two (2) electrons and the next shell that follows can have a maximum of eight (8).
The fewer electrons an atom has on its outer shell the more easily they lose. For example
FAIR TEST
- To the risk of contamination I will clean the apparatus before use
- I will allow time for the reaction to end and the solution to settle
-
After retrieving the FeSO4 I will allow time for it to dry. This will help avoid a wrong weight for any water contents can increase the weight
- I will be heating the solution gently to so that it does not splash (this reduces the risk of losing too much)
SAFETY
Sulphuric acids may cause skin irritation or evens burns depending on their concentration. It may be fatal if it gets direct contact with naked skin or eyes. To avoid this, wear eye protection, rubber gloves and protective clothing. In case of contact with eyes and skin, immediately run water on the area. Seek quick medical advice for eyes. Any contaminated cloths should be thoroughly cleaned before it is re-used. In the case of swallowing Sulphuric acid Solution, drink large amounts of water or milk. Do not vomit if possible.
Calculating the relative molecular mass (RMM)
A molecule consists of atoms joined together. The mass of a molecule will be the total of all the atomic masses added up. This is called RMM
For example to calculate the relative atomic mass of
Copper sulphate 5H2O
Cu + S + O4 + 5(H2 + O)
63+ 32+16(4) +5(2+16)
CuSO4 5H2O 63+32+16(4)+5(2+16) 63+32+64+90 249g
Iron II sulphate 7H2O
Fe + S + O4 + 7(H2 + O)
56+32+16(4) +7(2+16)
FeSO4 7H2O 56+32+16(4) +7(2+16) 56+32+64+126 278g
Calculating theoretical yield
The theoretical yield is the maximum amount of product that can be made. In other words it is a 100% of the yield
From the equations above (under the RMM subheading) we found that the relative molecular mass of;
Copper sulphate 5H2O to be 249g and
Iron II sulphate 7H2O to be 278g
These means that
249g of CuSO4 makes 278g of FeSO4
In my experiment I used 5g of CuSO4.
I know that 249g of CuSO4 makes 278g of FeSO4
So to find how many grams this makes I will divide 278 by 249 and multiply it by 5
278÷279×5 5.58
this is know my 100
Why the weight is less
- Transferring the substances from one container to another. This will affect the weight in that it is practically not possible to transfer a 100% of a given substance.
- The more greater the number of operations the more the chance of losing some at every stage
- Though measures were taken to avoid, when heating the solution there were times when it splashed out hence losing some substances
Improving the yield
I would think that taking the following into consideration would have improved my actual yield:
- Giving more time for the reaction to end
- Transferring the substances as few times as possible and Make sure that I transfer the as much of the substance as possible (this is to make sure that there are as few of the substance lost in the transferring as possible.
Drugs manufacturing in pharmaceutical industry
Drugs manufacturing industry has a great concern for quality. This is to say they want to make products ‘right first time’ without any flaws or defects. This called Total Quality Management (TQM). There are three main aspects of TQM that are distinctive to the Pharmaceutical industry
Long developing time
Once a promising molecule has been found, it can take up to 12 years of producing and testing to the launch of the medicine. This is to allow the company to ensure that the medicine is acceptably safe for use.
The licence and the production processes.
In the pharmaceutical industry a licence has to be granted before a medicine can be produced. Its issue depends on the production process. Therefore, once the licence has been issued, it is very difficult to change the process. This means that the production process must be carefully planned at the very beginning.
Overriding concern for safety
This can be seen by the use of strict systems.
Quality control is operation of methods and procedures for measuring, recoding and maintaining the level of quality
It includes:
- Checking the safety of a medicine through extensive trials
-
A for tracking each stage in the production of a batch
- Heavy investment in training.
Pharmaceutical companies devote a lot of time to training. They encourage their staff to take responsibility for their work.
EVALUATION
This experiment was hard to do and has not gone as expected.
As per the instructions given, we were to use between 4.8 to 5.2 grams of copper sulphate and 1.5g of iron filings. After dissolving the copper sulphate the solution turned blue as expected but after adding the iron filings I expected the solution to turn pale green after the redox reaction has occurred. This did not happen. Although copper metal was precipitated the solution remained blue which means there was copper present. After I repeated the procedure several times to make sure that I got it right and ended up with the same result, it made me think that I the ratio of copper sulphate to the iron given in the instruction sheet was not right. I tried to work out the ratios to find this. Bellow is the calculation I did:
RMM for
CuSO4 5H2O 249g (see ‘calculating RMM’)
RAM for
Fe 56
1g of CuSO4 5H2O ≡ 56÷249
In my experiment I used 5g therefore
5g of CuSO4 5H2O ≡ 56÷249×5 = 1.12
This shows that the amount of iron is even in excess which is contrary to what I thought.
Then I thought that there was an equilibrium and decided to add more irons to push it over. I first increased the amount of the iron filings to 4.8g but this did not work either and the problem was the same.
I then tried to half the amount of copper sulphate (make it 2.5g) and 4.8g of iron filings to try again to push the equilibrium over.
This also didn’t turn the colour of the solution.
The same problem came up after every trial. I now strongly feel that the problem lied on the reaction of the iron. It is possible that the copper coated the iron filings and stopped the most of it from the reaction.
SUGESTIONS ON IMROVING THE REACTION
- One of the things that may have help will be to get keep on increasing the amount of iron and try to push the equilibrium over.
- Another thing that can be done is grinding the iron to very small particles so that it reacts well and quick
