Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Presence of which among the following minerals in Banana makes them slightly radioactive?
[A] Sodium
[B] Calcium
[C] Magnesium
[D] Pottasium
Show Answer
Correct Answer: D [Pottasium]
Notes:
Bananas contain potassium-40, a radioactive isotope of potassium, which makes them slightly radioactive. The radiation is very minor and not dangerous at all to humans, but it is enough to trigger sensitive radiation sensors. The potassium provides bananas some of their nutritional benefits as well.
2. Which among the following elements are generally find in free state?
[A] Group 11 elements
[B] Group 12 elements
[C] Group 13 elements
[D] Group 14 elements
Show Answer
Correct Answer: A [Group 11 elements ]
Notes:
Group 11 is also known as the coinage metals, due to their former usage. They were most likely the first three elements discovered. Copper, silver, and gold all occur naturally in elemental form.
3. Consider the following:
- Cinnabar is also known as mercurblende
- The color of Cinnabar varies from dull grey to bright green
- Cinnabar is the most common source ore for refining elemental mercury
- Cinnabar is the historic source for the brilliant blue pigment termed azure
Which of the statements given above are correct?
[A] Only 1 and 3
[B] Only 2 and 4
[C] 1, 3 and 4
[D] All Four
Show Answer
Correct Answer: A [Only 1 and 3]
Notes:
Cinnabar, also known as mercurblende, is indeed the most common ore source for refining elemental mercury. However, its color range runs from scarlet to brick-red, not grey to green. It is known for providing the brilliant red or scarlet pigment known as vermilion, not a blue pigment.
4. Cassiterite is most important source of which of these metals?
[A] Nickel
[B] Tin
[C] Tungsten
[D] Silver
Show Answer
Correct Answer: B [Tin ]
Notes:
Cassiterite is a mineral that is primarily composed of tin dioxide (SnO2). It is the most important source of tin, and is also used as a semi-precious gemstone. Cassiterite is typically found in igneous and metamorphic rocks, and is often associated with other minerals such as quartz, feldspar, and mica. It has a high melting point and is resistant to weathering, making it a useful material for many industrial applications. The name “cassiterite” comes from the Greek word “kassiteros,” which means “tin.”
5. Which of the following chemicals is also known as "sweet oil of vitriol"?
[A] Diethyl ether
[B] Aluminium sulphate
[C] Sulphuric acid
[D] Iron(III) sulphate
Show Answer
Correct Answer: A [ Diethyl ether]
Notes:
Diethyl ether is a colourless, highly volatile & flammable organic compound. It was earlier used for anaesthesia but after the development of non-flammable drugs, its uses as anaesthetic has been reduced.
6. Which of the following chemicals is called Philosopher’s Wool?
[A] Brimstone
[B] Zinc oxide
[C] Magnesium hydroxide
[D] Potassium nitrate
Show Answer
Correct Answer: B [ Zinc oxide]
Notes:
The compound zinc oxide (ZnO) is called philosopher's wool. ZnO is a white powder that is insoluble in water. Zinc oxide is used as an additive in sun screens, sun lotions, in rubber manufacturing and in photocopying products. Alchemists, as part of their rituals, burn zinc in air and collect the residue, which formed into white woolly tufts. They called it Lana philosophica in Latin, meaning philosopher's wool.
7. Which of the following is NOT correct about Group 14 elements?
[A] All of them are solids
[B] Melting points are much higher than those of corresponding elements of group 13
[C] Carbon is a non-metal
[D] Germanium is a metal
Show Answer
Correct Answer: D [Germanium is a metal]
Notes:
All members of group 14 are solids. Carbon and silicon are non-metals, germanium is a metalloid, whereas tin and lead are soft metals. Melting points and boiling points of group 14 elements are much higher than those of corresponding elements of group 13.
8. Which of the following elements have a compound named as Hydrogen peroxide?
[A] Hydrogen, Carbon and Oxygen
[B] Hydrogen only
[C] Hydrogen and Oxygen
[D] Hydrogen, Oxygen and Potassium
Show Answer
Correct Answer: C [Hydrogen and Oxygen]
Notes:
Hydrogen peroxide is a compound of Hydrogen and Oxygen.
9. Which of the following is correct about suspension?
[A] It is a heterogeneous mixture
[B] The particles of a suspension can be seen by naked eyes
[C] The particles can be separated from the mixture by the process of filtration
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Suspension is a heterogeneous mixture. The particles of a suspension can be seen by the naked eye. The solute particles can be separated from the mixture by the process of filtration.
10. What are the constituents of German Silver alloy?
[A] Gold, Aluminium and Copper
[B] Zinc, iron and Silver
[C] Bismuth, Antimony and Tin
[D] Copper, Nickel and Zinc
Show Answer
Correct Answer: D [Copper, Nickel and Zinc]
Notes:
German silver is a copper alloy with nickel and zinc. It is also known as Nickel silver or Maillechort. The usual composition is 60% copper, 20% nickel and 20% zinc.
