Sulphur Dioxide when dissolved in water forms-
- A.Sulphur Trioxide
- B.Sulphurous acid
- C.Sulphuric acid
- D.Sulphur
Correct answer
Explanation
The correct answer is B, sulphurous acid. Sulphur dioxide dissolves in water to give sulphurous acid, a weak acid with the formula H2SO3, by the reaction SO2 + H2O to H2SO3. Sulphur dioxide is an oxide of a non-metal, and such oxides are acidic in nature, which is why the solution turns blue litmus red. The same gas, released when coal and diesel burn, dissolves in rain water in the air and is then slowly oxidised further, so sulphur dioxide is one of the main causes of acid rain. A is wrong because sulphur trioxide is made by oxidising sulphur dioxide with more oxygen over a catalyst, not by dissolving it in water. C is wrong because sulphuric acid is formed when sulphur trioxide, and not sulphur dioxide, meets water. D is wrong because sulphur is the element itself and cannot be got back simply by dissolving its oxide. Exam tip: SO2 with water gives H2SO3; SO3 with water gives H2SO4.
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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In 1609 Kepler showed that the planets move around the Sun in elliptical orbits, with the Sun at one focus of the ellipse.
Read the full explanation →Which one of the following statements is correct?
- A.Urea is produced in liver.
- 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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Liver cells turn the toxic ammonia released from the breakdown of amino acids into urea through the ornithine cycle, also called the urea cycle.
Read the full explanation →Which one of the following is the correct sequence of passage of light in a compound microscope?
- 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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Light passes through the condenser to the specimen, is picked up by the objective lens, travels up the body tube and reaches the eye through the eyepiece.
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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It binds oxygen at its iron-containing haem groups and carries some carbon dioxide on its protein chains. Each haemoglobin molecule has four polypeptide chains and four haem groups, and each haem iron can hold one oxygen molecule, forming oxyhaemoglobin in the lungs.
Read the full explanation →Which one of the following statements regarding histone proteins is correct?
- A.Histones are proteins that are present in mitochondrial membrane.
- 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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They are the proteins around which DNA winds to form chromatin in the nucleus of eukaryotic cells. Histones are small basic proteins, rich in the positively charged amino acids lysine and arginine, which attract the negatively charged phosphate groups of DNA.
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