Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
41. What is the chemical name of quick lime?
[A] Calcium carbonate
[B] Sodium hydroxide
[C] Calcium oxide
[D] Calcium sulphate
Show Answer
Correct Answer: C [Calcium oxide]
Notes:Calcium oxide (CaO) is commonly known as quicklime. The raw material used for the manufacture of quicklime is calcium carbonate (CaCO3). Lime is manufactured by heating the calcium carbonate to a temperature of 1273K in a lime kiln.
- CaCO3 (Lime stone) —> CaO (Lime) + CO2 (Carbon dioxide)
42. Thermal electricity is generated by using which of these?
[A] Coal only
[B] Coal and Natural Gas only
[C] Coal, Natural Gas and Petroleum
[D] None of the above
Show Answer
Correct Answer: C [Coal, Natural Gas and Petroleum]
Notes:
A thermal power station is a power plant in which heat energy is converted to electric power. Thermal power plant uses fossil fuel such as coal, natural gas or petroleum. More than 65% of India’s electricity generation capacity comes from thermal power plants, with about 85% of the country’s thermal power generation being coal-based.
43. Which of the following is used for the preparation of dynamite?
[A] Methyl alcohol
[B] Iron oxide
[C] Nitro Glycerol
[D] Copper sulphate
Show Answer
Correct Answer: C [Nitro Glycerol]
Notes:
Nitroglycerin (NG), also known as trinitroglycerin (TNG), is a powerful explosive and an important ingredient of most forms of dynamite. It is also used with nitrocellulose in some propellants, especially for rockets and missiles. Swedish chemist Alfred B. Nobel developed dynamite in the 1860s by combining liquid nitroglycerin with an inert porous material such as charcoal or diatomaceous earth.
44. Ethanol containing 5% water is known as:
[A] Dilute alcohol
[B] Power alcohol
[C] Rectified spirit
[D] Absolute alcohol
Show Answer
Correct Answer: C [Rectified spirit]
Notes:
A rectified alcohol is highly concentrated ethanol which has been purified by means of repeated distillation, a process that is called rectification. It typically contains 95% alcohol by volume and 5% water. Normally, ethanol with 5% water is known as pure alcohol.
45. Chemical name of Gammaxane is:
[A] Toluene
[B] Chloro benzene
[C] Aniline
[D] Benzene hexachloride
Show Answer
Correct Answer: D [Benzene hexachloride]
Notes:
Gammexane is an insecticide that is the gamma isomer of benzene hexachloride. It is also known as lindane. Benzene hexachloride is any of several stereoisomers of 1,2,3,4,5,6-hexachlorocyclohexane (C6H6Cl6) formed by the light-induced addition of chlorine to benzene.
46. If water smells bad, then that odour can be removed by adding:
[A] alum
[B] bleach
[C] activated carbon
[D] deactivated nitrogen
Show Answer
Correct Answer: C [activated carbon]
Notes:
Adding powdered activated carbon to water or using of granular activated carbon (GAC) in the water filter can remove bad taste and foul odor. Powdered activated carbon (PAC) is the preferred method when the taste and odor is moderate and infrequent. Activated carbon works by a phenomenon called “Adsorption”, which is where the odor compound is trapped inside the activated carbon and retained, but the material doing the adsorption does not change size.
47. Who is the only scientist in the world to have won the Nobel prize in Chemistry twice?
[A] Linus Carl Pauling
[B] Roger D. Kornberg
[C] Madame Curie
[D] Frederick Sanger
Show Answer
Correct Answer: D [Frederick Sanger]
Notes:- Sanger is the only person to have been awarded the Nobel Prize in Chemistry twice. (a) He is one of only four two-time Nobel laureates. (b) The other three were
- Marie Curie (Physics, 1903 and Chemistry, 1911)
- Linus Pauling (Chemistry, 1954 and Peace, 1962)
- John Bardeen (twice Physics, 1956 and 1972).
48. Tartaric Acid is not found in:
[A] Tamarind
[B] Grapes
[C] Unripe mangoes
[D] Spinach
Show Answer
Correct Answer: D [Spinach]
Notes:
Tartaric acid is a white crystalline organic acid. It occurs naturally in many plants, particularly grapes, unripe mangoes and tamarinds, and is one of the main acids found in wine. It is added to other foods to give a sour taste, and is used as an antioxidant. Oxalic acid is found in spinach.
49. Which of the following acids is present in ant bites?
[A] Formic acid
[B] Malic acid
[C] Perchloric acid
[D] Nitric acid
Show Answer
Correct Answer: A [Formic acid]
Notes:
Formic acid (HCO2H) occurs naturally, most notably in some ants. The word ‘‘formic’’ comes from the Latin word for ant, formica, referring to its early isolation by the distillation of ant bodies. It is this compound that causes most of the irritation that occurs immediately following an ant bite or a bee sting.
50. A biochemical compound is any:
[A] mineral-based compound found in living things
[B] sulfur-based compound found in living things
[C] carbon-based compound found in living things
[D] hydrogen-based compound found in living things
Show Answer
Correct Answer: C [carbon-based compound found in living things]
Notes:
Biochemical compounds are made up of various elements and molecules. The most common elements found in biochemical compounds are carbon, hydrogen, oxygen, and nitrogen. These elements combine to form molecules such as carbohydrates, lipids, proteins, and nucleic acids. These molecules, in turn, can be further broken down into smaller units, such as amino acids and nucleotides. The specific components of a biochemical compound depend on the particular compound in question and its role in the organism.
