2NaOH (aq) + H2SO4 (aq) → Na2SO4 (aq) + 2H2O (l). The given reaction is an example of:
- A.precipitation reaction
- B.decomposition reaction
- C.neutralisation reaction
- D.redox reaction
Correct answer
Explanation
The correct answer is C, neutralisation reaction. In the given equation sodium hydroxide, which is a base, reacts with sulphuric acid to give sodium sulphate and water, and a reaction in which an acid and a base cancel each other to form a salt and water is called neutralisation. Its general form is acid plus base gives salt plus water, and heat is given out, so the reaction is exothermic. Two molecules of sodium hydroxide are needed here because sulphuric acid is dibasic and supplies two hydrogen ions. Everyday examples are an antacid taken for acidity in the stomach, lime spread on an acidic soil and baking soda rubbed on a bee sting. A is wrong because a precipitation reaction forms an insoluble solid, while both products here stay in solution. B is wrong because in a decomposition reaction a single compound splits into two or more simpler substances. D is wrong because a redox reaction involves a change in oxidation numbers, and here they do not change. Exam tip: acid plus base giving salt and water is always neutralisation.
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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