1. Which of the following are the most and the least electronegative elements in the periodic table?
[A] Fluorine and Caesium
[B] Hydrogen and Helium
[C] Carbon and Oxygen
[D] Chlorine and Fluorine
Show Answer
Correct Answer: A [Fluorine and Caesium]
Notes:
Caesium is the least electronegative element in the periodic table and Fluorine is the most electronegative. Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.
2. Which of the following is the essential element for batteries used in electric cars?
[A] Magnesium
[B] Lithium
[C] Sodium
[D] Bromine
Show Answer
Correct Answer: B [ Lithium ]
Notes:
The lithium-ion batteries needed to power electric cars use lithium carbonate or lithium hydroxide.
3. Which among the following is a Noble Gas?
[A] Nitrogen
[B] Hydrogen
[C] Oxygen
[D] Helium
Show Answer
Correct Answer: D [Helium]
4. Which among the following is responsible for depletion of Ozone?
[A] Carbon monoxide
[B] Carbon dioxide
[C] Chlorofluoro carbon
[D] Mercuric oxide
Show Answer
Correct Answer: C [Chlorofluoro carbon ]
5. Which among the following are constituents of Brass?
[A] Zinc and Copper
[B] Iron and Zinc
[C] Copper and Nickel
[D] Iron and Copper
Show Answer
Correct Answer: A [Zinc and Copper ]
6. Identify the non-metallic mineral from the given options:
[A] Manganese
[B] Magnesium
[C] Silica
[D] Bauxite
Show Answer
Correct Answer: C [Silica]
7. The aqueous solution of which among the following acids is called Vinegar?
[A] Oxalic acid
[B] Citric acid
[C] Acetic acid
[D] Hydrochloric acid
Show Answer
Correct Answer: C [Acetic acid ]
8. Which among the following chemicals is used in Photography?
[A] Silver Bromide
[B] Potassium Chloride
[C] Sodium Bromide
[D] Magnesium Chloride
Show Answer
Correct Answer: A [Silver Bromide]
9. When Sulphur is heated with rubber, the process is commonly known as ?
[A] Galvanization
[B] Sulphonation
[C] Vulcanization
[D] Hydrodesulfurization
Show Answer
Correct Answer: C [Vulcanization]
Notes:
Natural rubber becomes soft at high temperature (>335 K) and brittle at low temperatures (<283 k) and shows high water absorption capacity. It is soluble in non-polar solvents and is non-resistant to attack by oxidising agents. To improve upon these physical properties, a process of vulcanisation is carried out. This process consists of heating a mixture of raw rubber with sulphur and an appropriate additive at a temperature range between 373 K to 415 K. On vulcanisation, sulphur forms cross links at the reactive sites of double bonds and thus the rubber gets stiffened.
In the manufacture of tyre rubber, 5% of sulphur is used as a crosslinking agent
10. Which of the following type of Coal, has maximum carbon content?
[A] Peat
[B] Lignite
[C] Antharacite
[D] Bituminious
Show Answer
Correct Answer: C [Antharacite]
