Q1. Dirty cloths containing grease and oil stains are cleaned by adding detergents to water. Stains are removed because detergent
(a) reduces drastically the surface tension between water and oil
(b) increases the surface tension between water and oil
(c) increases the viscosity of water and oil
(d) decreases the viscosity in detergent mixed water
(e) None of the above
Q2. Fire fly gives us cold light by virtue of the phenomenon of
(a) fluorescence
(b) phosphorescence
(c) chemiluminescence
(d) effervescence
(e) None of the above
Q3. Which one among the following metals is used for making boats because it does not corrode by sea water?
(a) Tungsten
(b) Nickel
(c) Antimony
(d) Titanium
(e) None of the above
Q4. A close bottle containing water at room temperature was taken to the Moon and then the lid is opened. The water will
(a) freeze
(b) boil
(c) decompose into oxygen and hydrogen
(d) not change at all
(e) None of the above
Q5. On the labels of the bottles, some soft drinks are claimed to be acidity regulators. They regulate acidity using
(a) carbon dioxide
(b) bicarbonate salts
(c) Both (a) and (b)
(d) carbon dioxide and lime
(e) None of the above
Q6. Which one among the following is responsible for the expansion of water in the ocean?
(a) Carbon dioxide
(b) Nitrogen dioxide
(c) Carbon monoxide
(d) Sulphur dioxide
(e) None of the above
Q7. Food cans are coated with tin but not with zinc because
(a) zinc is costlier than tin
(b) zinc has a higher melting point than tin
(c) zinc is more reactive than tin
(d) tin is more reactive than zinc
(e) None of the above
Q8. Date of manufacture of food items fried in oil should be checked before buying because oils become rancid due to
(a) oxidation
(b) reduction
(c) hydrogenation
(d) decrease in viscosity
(e) None of the above
Q9. A woman desires to clean the surface of her gold ornaments by a chemical approach. For this she requires to use
(a) aqua-regia
(b) concentrated H2SO4
(c) concentrated NaOH
(d) sodium thiosulphate solution
(e) None of the above
Q10. Which one of the following is not needed in a nuclear fission reactor?
(a) Moderator
(b) Coolant
(c) Accelerator
(d) Control device
(e) None of the above
Solutions
S1.Ans. (a)
Sol. One end of hairpin shaped detergents attracted to water and other to molecules of oil or grease that reduces drastically the surface tension between water and oil.
S2.Ans. (c)
Sol. Fire fly gives us cold light due to chemiluminescence i.e. light produced by chemical reaction.
S3.Ans. (d)
Sol. Titanium (Ti) metal is used for making boats because it does not corrode by the sea water.
S4.Ans. (a)
Sol. The water will freeze because on Moon the temperature is below the freezing point i.e., very low.
S5.Ans. (b)
Sol. In soft drinks bicarbonate salts acts as acidity regulators. Bicarbonate of soda is effective at regulating the pH levels of other substances; it ensures that the substance is neither too alkaline nor too acidic.
S6.Ans. (a)
Sol. Carbon dioxide is responsible for the expansion of water in the ocean, CO2 causes global warming.
S7.Ans. (c)
Sol. Food cans are coated with tin instead of zinc because zinc is more reactive than tin. Tin is only reactive to powerful acids such as tri-sodium phosphate, while zinc is reactive towards acids.
S8.Ans. (a)
Sol. Oil become rancid due to oxidation oil contains fatty acid which react in presence of oxygen and become rancid. Rancid oil is a major source of destructive free radicals in our diet.
S9.Ans. (a)
Sol. Aqua-regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid in the ratio of 1: 3. It is a very powerful oxidising mixture and hence, used to clean the surface of gold ornaments. Coolant like heavy water or molten sodium is used to carry away the heat.
S10.Ans. (c)
Sol. Substances like graphite and heavy water are used as moderator to slow down the speed of neutrons. Cd or B are used as control rods to control rate of fission by absorbing neutrons.
General-Studies Quiz For FCI Phase I 202...
