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 Mg atom has 12 electrons therefore its electronic configuration is 2, 8, 2. This means it outer shell has only 2 electrons making it easier for it to lose electrons.
In MgCO3 the mg atom loses the two 2 electrons on its outer shell making it Mg2+ while the CO3 gains 2 electrons to make CO3 2-
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
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After retrieving the MgCO3 I will allow time for it to dry. This will help avoid a wrong weight for any water contents can increase the weight
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
To calculate the relative molecular mass of a molecule we add up the atomic masses of the atoms that make up the molecule.
For example MgCO3 molecule consist of magnesium, carbon and 3oxygen so to calculate its RMM we add up the atomic masses of magnesium, carbon and 3oxygen
For example
Mg + S + O4 Mg + C + O3
24 + 32 +16(4) 24 + 12 + 16(3)
MgSO4 24+32+16(4) 24+32+64 120g
MgCO3 24+12+16(3) 24+12+48 84g
Calculating theoretical yield
The theoretical yield is the maximum amount of product that can be made.
You will need…..
Mg + S + O4 to make Mg + C + O3
24 + 32 +16(4) 24 + 12 + 16(3)
This means…..
MgSO4
Mg + S + O4
24 + 32 + 16(4) 24+32+64 120g (RMM)
……you will need 120g MgSO4….
MgCO3
Mg + C + O3
24 +12 + 16(3) 24+12+48 84g (RMM)
…..to make 84g MgCO3
In my experiment I will be using 3g of MgSO4.
If 120g of MgSO4 can make 84g of MgCO3, to find what 1g of MgSO4 will make I will divide 84 by 120
84/120 0.7g
This means 1 gram of MgSO4 makes 0.7g of MgCO3.
Therefore for 3g of MgSO4 I will multiply it by 3, which will make 2.1g of MgCO3.
So the theoretical yield (100% yield) is 2.1g MgCO3
Calculating % yield
The actual yield is the amount obtained from after the experiment.
To calculate the percentage actual yield we divide the actual yield by the theoretical and multiply it by a hundred.
My actual yield was 1g of MgCO3 and my theoretical yield 2.1g MgCO3
Therefore percentage yield is
1 x 100 47.62%
2.1
Why the weight is less
The above equations show that out of 100% yield, I got 47.62 which will mean I lost 53.38% of the yield. This may be as a result of a number of factors which include:
- Some of the solution may have escaped from the sides of the filter paper
- 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 the number of operations (steps) the more the chance of losing some at every stage
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).
- Cooling the mixture so that the precipitant can settle
- Adapting a different method with fewer operations (steps)
USES OF MgCO3
The MgCO3 is a stomach anti-acid and is present in various laxatives. It can be used as a base in the treatment of dyspepsia, gout and other diseases. In dentistry, MgCO3 is used in the gypsum impressions from which dental plates are made.
Magnesium carbonate is also used as anti-caking agent in the cooking salt.
MgCO3 is used as carbonate source in the soft drinks. In cattle feeds, the It also provides the magnesium required in the animal's diet.
Plants need magnesium to make chlorophyll for photosynthesis
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
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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.
Bibliography
To gather this information for the research I used books as well as the internet. The books I used include:
- APPLIED SCIENCE GCSE DOUBLE AWARD (Hodder and Stoughton)
The internet site I visited was: