Tincture of iodine is an antiseptic for fresh wounds. It is a dilute solution of elemental iodine, which does not contain
- A.water
- B.acetone
- C.alcohol
- D.potassium iodide
Correct answer
Explanation
The correct answer is B, acetone. Tincture of iodine is made from iodine, potassium iodide, alcohol and water; acetone is not one of its ingredients.
A tincture is a solution in alcohol. Tincture of iodine is a 2-3 percent solution of iodine in a mixture of ethyl alcohol and water, with potassium iodide added. Iodine dissolves poorly in water alone, so potassium iodide is used: it reacts with iodine to form the soluble tri-iodide ion and keeps the iodine in solution. The iodine kills bacteria, fungi and viruses on the skin, which is why the brown solution is applied to fresh cuts and wounds.
Option A is wrong because water is part of the mixture used to dilute it. Option C is wrong because alcohol is the main solvent, which is what makes it a tincture. Option D is wrong because potassium iodide is added to help iodine dissolve.
Exam tip: tincture of iodine = iodine + potassium iodide in alcohol-water; "tincture" means an alcoholic solution.
Practice Questions
View allThe fact that the planets move around the Sun, not in circles but in ellipses, was first demonstrated by
- A.Galileo
- B.Martin Luther
- C.Johannes Kepler
- D.Copernicus
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- B.Urea is produced in blood.
- C.Urea is produced from digestion of starch.
- D.Urea is produced in lung and kidney.
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- A.Condenser-Objective lens-Eyepiece-Body tube
- B.Objective lens-Condenser-Body tube-Eyepiece
- C.Condenser-Objective lens-Body tube-Eyepiece
- D.Eyepiece-Objective lens-Body tube-Mirror
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Read the full explanation →Which one of the following statements regarding haemoglobin is correct?
- A.Haemoglobin present in RBC can carry only oxygen but not carbon dioxide.
- B.Haemoglobin of RBC can carry both oxygen and carbon dioxide.
- C.Haemoglobin of RBC can carry only carbon dioxide.
- D.Haemoglobin is only used for blood clotting and not for carrying gases.
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- B.Histones are proteins that are present in nucleus in association with DNA.
- C.Histones are proteins associated with lipids in the cytosol.
- D.Histones are proteins associated with carbohydrates in the cytosol.
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