Investigating iron tablets
Ferrous salts used as supplements by mouth include ferrous fumarate, ferrous
gluconate, ferrous succinate, and ferrous sulfate.
(1) Wikipedia (2024) Iron supplement
Available at:
https://en.wikipedia.org/wiki/Iron_supplement (accessed: 9 February 2024)
Iron helps the body to make healthy red blood cells which carry oxygen around the
body through haemoglobin and myoglobin. Haemoglobin is a protein in your red blood
cells. Haemoglobin helps your blood carry oxygen from your lungs to all your body‘s tissues
and organs. Myoglobin is a protein in your muscles and helps supply oxygen to the cells in
your muscles.
If you don’t have enough iron, your body can’t make these proteins, and you may develop
iron-deficiency anemia. Iron-deficiency anemia is the most common type of anemia. Anemia
is a blood disorder in which your body doesn’t have enough red blood cells.
(2) Cleveland Clinic (2024) Iron supplement (Ferrous Sulfate)
Available at:
https://my.clevelandclinic.org/health/drugs/14568-iron-oral-supplements-for-anemia
(accessed: 9 February 2024)
Iron supplements are used to treat or prevent iron deficiency and iron-deficiency anemia, where
requirements for iron are greater than the body's ability to supply iron such as in inflammatory
states.
If people have low iron stores in their body, then taking iron tablets may help to provide a
supplement of the mineral ion. Low iron stores may be caused by pregnancy, a diet low in
iron, conditions that decrease the body’s ability to absorb iron such as Crohn's disease,
celiac disease, heart failure, cancer, kidney failure.
The amount that should be consumed on a daily basis is called the recommended
dietary allowance (RDA). For males 19 years and older and females 51 years and
older, the RDA is 8 mg. For females 19-50 years of age, the RDA is 18 mg. While
pregnant, the RDA is 27 mg. While breast-feeding, the RDA is 10 mg for those 14-18
years of age, and 9 mg for those 19-50 years of age.
For adults and children ages 14 and up, the upper limit -- the highest dose that can be
taken safely -- is 45 mg a day. Children under age 14 should not take more than 40
mg a day.
(3) WebMD (2024) Dietary iron and iron supplements
Available at:
https://www.webmd.com/diet/supplement-guide-iron (accessed: 9 February 2024)
The active ingredient is ferrous sulfate 200mg equivalent to 65mg of ferrous iron Fe(II). The
other ingredients are: kaolin, glucose, povidone, stearic acid, magnesium stearate, sodium
lauryl sulfate, starch, opaglos, titanium dioxide (E171) and sucrose.
, (4) Medicine.org (2024) Ferrous sulfate 200mg coated tablets
Available at:
https://www.medicines.org.uk/emc/files/pil.3130.pdf (accessed: 9 February 2024)
Iron (II) ions can be oxidised to iron (III) ions by potassium manganate (VII) in acidic
solution, where the deep purple solution of manganate (VII) ions is reduced to a pale
pink solution of manganese (II) ions. This solution is so pale as to appear colourless
when dilute, therefore the marked difference in colour between these two oxidation
states is useful as an end-point for this redox reaction.
The manganate (VII) ion accepts electrons and is reduced to colourless Mn2+ ions
MnO4 – (aq) + 8H+ (aq) + 5e– Mn2+(aq) + 4H2O(l) (purple to colourless)
The electrons are provided by the iron (II) ions which act as the reducing agent. Fe 2+
(aq) à Fe (aq) + e
3+ –
The potassium manganate (VII) solution is added from the burette to the solution of
the reducing agent and is immediately decolourised.
As soon as the reducing agent is used up, the next drop of potassium manganate
(VII) solution is not decolourised and colours the solution in the conical flask a pale
purple colour (end-point). The acid used to provide H+ (aq) is dilute sulfuric acid, which
should always be in excess otherwise insoluble brown manganese (IV) oxide (MnO2)
will form.
Plan
Equipment
● 5 iron tablets
● 1 mol dm-3 sulfuric acid
● A solution of acidified potassium manganate (VII), KMnO4 (aq), approx.
0.0100 mol dm-3
● Weighing boat
● 100 cm3 conical flask
● Filter funnel and paper
● Distilled water
● 100 cm3 volumetric flask
● Burette stand and clamp
● 250 cm3 beaker
● 25 cm3 pipette
● 25 cm3 measuring cylinder
● 2 250 cm3 conical flasks
Method
