Which of the following statements is correct about suspension?
- A.A suspension is a heterogeneous mixture.
- B.Solids dispersed in gas are called suspensions.
- C.Particles of a suspension are invisible to the naked eye.
- D.A suspension is a homogeneous mixture.
Correct answer
Explanation
The correct answer is A, a suspension is a heterogeneous mixture. In a suspension the particles of the solute are large enough to be seen and do not dissolve; they stay spread through the liquid only while it is stirred and settle to the bottom when it is left standing. Chalk powder in water, muddy river water and a shaken bottle of paint are everyday examples. Because the particles are big, a suspension scatters a beam of light, showing the Tyndall effect, and the particles can be separated by filtration. B is wrong because solids spread in a gas, such as smoke, are aerosols, a kind of colloid, not a suspension. C is wrong because the particles of a suspension are large enough to be seen with the naked eye; it is the particles of a solution that cannot be seen. D is wrong because a homogeneous mixture is a solution, which is uniform throughout. Exam tip: solution homogeneous, suspension heterogeneous and settles, colloid in between.
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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