Estimating Glucose Concentration in Solution
Introduction
Glucose is very important in our daily lives. It gives us energy to carry out all of our activities. Cells in our bodies need glucose to respire and in the process release the energy we need. Glucose is also a type of carbohydrate. It has a chemical formula of C6H12O6 and is a monosaccharide reducing sugar (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1). It is the simplest form of carbohydrate. In this experiment, sulphuric acid, H2SO4 and potassium permanganate, KMnO4 is added into glucose with different concentration and the time taken for the purple pink colour of potassium permanganate solution to change to colourless is recorded. This is because glucose donates electrons to the permanganate ions, causing it to change colour (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1).
MnO4- + 8H+ + 5e- ------> Mn2+ + 4H2O (Purple pink in (Colourless in solution) solution)
The manganate ion (MnO4-) is reduced to a colourless solution of manganese ion (Mn2+). As a result from this reaction, the glucose is oxidized (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1). The time taken for the potassium permanganate to change colour from purple pink to colourless is directly related to the concentration of glucose present in solution (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1).
Research question : How does the different concentration of glucose in solution affects the time taken by potassium permanganate to change colour from purple pink to colourless?
Hypothesis : The higher the concentration of glucose in a solution, the shorter the time taken by potassium permanganate solution to change colour from purple pink to colourless. This is because the more concentrated the
Glucose is very important in our daily lives. It gives us energy to carry out all of our activities. Cells in our bodies need glucose to respire and in the process release the energy we need. Glucose is also a type of carbohydrate. It has a chemical formula of C6H12O6 and is a monosaccharide reducing sugar (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1). It is the simplest form of carbohydrate. In this experiment, sulphuric acid, H2SO4 and potassium permanganate, KMnO4 is added into glucose with different concentration and the time taken for the purple pink colour of potassium permanganate solution to change to colourless is recorded. This is because glucose donates electrons to the permanganate ions, causing it to change colour (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1).
MnO4- + 8H+ + 5e- ------> Mn2+ + 4H2O (Purple pink in (Colourless in solution) solution)
The manganate ion (MnO4-) is reduced to a colourless solution of manganese ion (Mn2+). As a result from this reaction, the glucose is oxidized (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1). The time taken for the potassium permanganate to change colour from purple pink to colourless is directly related to the concentration of glucose present in solution (Kolej Mara Banting – Students’ Handbook for Biology HL Year 1).
Research question : How does the different concentration of glucose in solution affects the time taken by potassium permanganate to change colour from purple pink to colourless?
Hypothesis : The higher the concentration of glucose in a solution, the shorter the time taken by potassium permanganate solution to change colour from purple pink to colourless. This is because the more concentrated the
References: Kolej Mara Banting – Students’ Handbook for Biology HL Year 1 www.saps.org.uk/attachments/article