The acid present in the sting of an ant is
- A.Formic acid
- B.Citric acid
- C.Lactic acid
- D.Tartaric acid
Correct answer
Explanation
The correct answer is A, formic acid. The sting of an ant and the hairs of the nettle plant inject formic acid, also called methanoic acid, which is why the skin burns; rubbing on a mild base such as baking soda or the leaf of the dock plant relieves it by neutralising the acid. Option B is wrong because citric acid belongs to lemon, orange and other citrus fruits. Option C is wrong because lactic acid is formed in curd and sour milk, and also in muscles during heavy exercise. Option D is wrong because tartaric acid is found in tamarind and grapes and is used with baking soda in baking powder. This question is a favourite because it also carries a neutralisation idea with it: the treatment for an acidic ant sting is a base, while a wasp sting, which is alkaline, is treated with a mild acid such as vinegar.
Read the full article: Acids, Bases and Salts: pH Scale and Common Salts
Practice Questions
View allWhich of the following contains citric acid?
- A.Tomato
- B.Orange
- C.Tamarind
- D.Sour milk
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Citrus fruits such as orange, lemon, lime and grapefruit owe their sharp sour taste to citric acid, which is the acid textbooks name for this family and the one examiners expect here.
Read the full explanation →The pH of a solution is 3. When its pH changes to 6, then the hydrogen ion concentration
- A.Increases 2 times
- B.Increases three times
- C.Decreases 100 times
- D.Decreases 1000 times
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The pH is the negative logarithm of the hydrogen ion concentration, so each rise of one unit means the concentration has fallen to one tenth.
Read the full explanation →When litmus is added to a solution of borax, it turns _______.
- A.Pink
- B.Orange
- C.Red
- D.Blue
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Borax, sodium tetraborate, is the salt of a strong base, sodium hydroxide, and a weak acid, boric acid, so its solution in water is basic.
Read the full explanation →What is the chemical formula of baking soda?
- A.Na2CO3
- B.NaHCO3
- C.NaOH
- D.CaOCl2
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Baking soda is sodium hydrogen carbonate, a mild, non corrosive base used as an antacid, as an ingredient of baking powder along with a mild edible acid such as tartaric acid, and in soda acid fire extinguishers, where it releases carbon dioxide.
Read the full explanation →Plaster of Paris is obtained by heating which of the following?
- A.Limestone
- B.Gypsum
- C.Quick lime
- D.Washing soda
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Plaster of Paris is calcium sulphate hemihydrate, made by heating gypsum, which is calcium sulphate dihydrate, to about 373 kelvin so that it loses three fourths of its water of crystallisation.
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