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
1. Which of the following is the poorest conductor of heat in comparison to other options?
[A] Silver
[B] Copper
[C] Lead
[D] Mercury
Show Answer
Correct Answer: C [ Lead ]
Notes:
Silver is best conductor of heat while among metals lead is poorest conductor of heat. Cooper and aluminum are good conductor while mercury is a poor conductor.
2. Which among the following is different from others given in option?
[A] Thiodan
[B] Thionex
[C] Benzoepin
[D] Toxaphene
Show Answer
Correct Answer: D [Toxaphene]
Notes:
Toxaphene, All are pesticides BUT rest three are names of Endosulfan
3. Which among the following is the objective of the Methyl tert-butyl ether (MTBE) mixing with Petroleum?
[A] Raise Octane Number
[B] Antioxidant Stabilizer
[C] Lead Scavanger
[D] Fuel Dye
Show Answer
Correct Answer: A [Raise Octane Number ]
Notes:
MTBE is a gasoline additive, used as an oxygenate to raise the octane number. Its use is controversial in the US and declining in that country in part because of its occurrence in groundwater and legislation favoring ethanol.
4. Which among the following types of glasses contains Cerium and other rare earths and has a high absorption of ultraviolet rays?
[A] Crookes Glass
[B] Pyrex Glass
[C] Flint Glass
[D] Crown Glass
Show Answer
Correct Answer: A [Crookes Glass]
Notes:
Crookes glass comprises Cerium oxide (CiO2) which sharply absorbs the ultraviolet rays from the sunlight. It is used in making lenses of eye glasses.
5. Highest percentage of nitrogen is found in which among the following fertilizers among the given options?
[A] Calcium ammonium nitrate
[B] Ammonium nitrate
[C] Calcium nitrate
[D] Urea
Show Answer
Correct Answer: D [Urea]
Notes:
The agricultural industry widely uses urea, a white crystalline solid containing 46 percent nitrogen as an animal feed additive and fertilizer. Urea has the highest nitrogen content of all solid fertilizers at 46% N.
6. Consider the nature and characteristics of Mustard Gas:
- It is a cytotoxic chemical warfare agent
- It has the ability to form large blisters on exposed skin
- It contains Sulphur as a key element
- It contains Magnesium as a key element
Which of the above statements is / are correct?
[A] Only 1 and 2
[B] Only 3
[C] 1, 2 and 3
[D] All four
Show Answer
Correct Answer: C [1, 2 and 3]
Notes:
Mustard Gas is a potent cytotoxic chemical warfare agent which can form large blisters on exposed skin and mucosa. Its formula is C4H8Cl2S which indicates that it contains the element Sulphur. It does not contain Magnesium.
7. Which among the following was the first artificially produced element?
[A] Neptunium
[B] Ununbium
[C] Technetium
[D] none of the above
Show Answer
Correct Answer: C [Technetium]
Notes:
Technetium was the first artificially produced element. It was isolated by Carlo Perrier and Emilio Segrè in 1937. Technetium was created by bombarding molybdenum atoms with deuterons that had been accelerated by a device called a cyclotron.
8. Which of the following substances is not considered as toxic pollutant of water?
[A] Carbonic acid
[B] Lead
[C] Mercury
[D] Cadmium
Show Answer
Correct Answer: A [ Carbonic acid ]
Notes:
Carbonic acid is formed when carbon dioxide combines with water. Carbon dioxide is an asphyxiant gas and is not classified as toxic or harmful in accordance with Globally Harmonized System of Classification and Labelling of Chemicals standards.
9. What is the dimensional formula of Stress?
[A] M 1 L-2 T-2
[B] M 1 L-1 T-1
[C] M 1 L1 T-3
[D] M 1 L-1 T-2
Show Answer
Correct Answer: D [M 1 L-1 T-2]
Notes:
Stress is defined as external force per unit area on a body that tends to cause it to deform. The dimensional formula of Stress is M 1 L-1 T-2
10. Which of the following is correct about the first ionization enthalpy of alkaline earth metals?
[A] It is higher than corresponding Group 1 metals
[B] It is lower than corresponding Group 1 metals
[C] No fix pattern exist
[D] None of the above
Show Answer
Correct Answer: A [It is higher than corresponding Group 1 metals]
Notes:
The first ionization enthalpy of these metals is higher than corresponding Group 1 metals due to the small size of these elements compared to the corresponding alkali metals. The second ionization enthalpy of these metals is lower than corresponding alkali metals.
