Which of the following has the chemical name as sodium hydrogen carbonate?
- A.Baking powder
- B.Baking soda
- C.Washing soda
- D.Plaster of Paris
Correct answer
Explanation
The correct answer is B, Baking soda. Its chemical name is sodium hydrogen carbonate and its formula is NaHCO3. It is a mild, non-corrosive base made by the Solvay process, in which brine is treated with ammonia and carbon dioxide. When heated it gives off carbon dioxide, which is why it makes cakes rise; it is also used in antacids, soda-acid fire extinguishers and as a cleaning agent. Note the trap in this question: baking soda and baking powder are different things. A is wrong because baking powder is a mixture of baking soda with a mild edible acid such as tartaric acid, not a single compound. C is wrong because washing soda is sodium carbonate decahydrate, Na2CO3.10H2O, used to soften hard water and in glass and soap making. D is wrong because plaster of Paris is calcium sulphate hemihydrate, CaSO4.1/2H2O, used for casts and moulds. Exam tip: baking soda NaHCO3, washing soda Na2CO3.10H2O, plaster of Paris CaSO4.1/2H2O, bleaching powder CaOCl2.
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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