Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Which among the following qualities of iron ore is best based upon iron content?
[A] Magnetite
[B] Hematite
[C] Limonite
[D] Siderite
Show Answer
Correct Answer: A [Magnetite]
Notes:
Magnetite, followed by Hematite – Limonite – Siderite
2. PVC is a polymer of__?
[A] Propane
[B] Vinyl chloride
[C] Styrene
[D] Carbonates
Show Answer
Correct Answer: B [Vinyl chloride]
Notes:
Polyvinyl chloride (PVC) is made from the monomer vinyl chloride (CH2 =CHCl). It is used for making raincoats, handbags, toys including dolls, electrical goods and as a covering of electrical wires.
3. The primary part of Liquefied Petroleum Gas LPG is ______?
[A] Butane
[B] Methane
[C] Propane
[D] Butane or Propane
Show Answer
Correct Answer: D [Butane or Propane]
Notes:
LPG consists mainly of propane, propylene, butane, and butylene in various mixtures. The primary gas can be either Propane or Butane.
4. Which among the following is an ionic solid?
[A] Diamond
[B] Dry ice
[C] Table salt
[D] All are ionic solids
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Correct Answer: C [Table salt]
Notes:
One important character of Ionic solids is that they readily get dissolved in water
5. Which of the following is the correct order of composition of biogas released through anaerobic bio-digester system?
[A] Methane> Carbon dioxide> Nitrogen> Hydrogen
[B] Carbon dioxide> Nitrogen> Methane> Hydrogen
[C] Nitrogen> Hydrogen> Carbon dioxide> Methane
[D] Hydrogen> Nitrogen> Methane> Carbon dioxide
Show Answer
Correct Answer: A [ Methane> Carbon dioxide> Nitrogen> Hydrogen ]
Notes:
The correct composition of biogas released through anaerobic bio-digester system is:
Methane (CH4) – 50–75 %
Carbon dioxide (CO2) – 25–50%
Nitrogen (N2) – 0–10%
Hydrogen (H2) – 0–1%
Hydrogen sulphide (H2S) – 0–3%
6. Which of the following is the use of washing soda?
[A] softening of water
[B] manufacture of glass
[C] manufacture of paints
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
It is used for softening of water, laundering, cleaning, manufacture of glass, soap, borax, paper, paints and textile It is also extensively used as laboratory reagent.
7. Which of the following is the composition of vinegar?
[A] 65-75% solution of acetic acid in water
[B] 45-60% solution of acetic acid in water
[C] 28-35% solution of acetic acid in water
[D] 5-8% solution of acetic acid in water
Show Answer
Correct Answer: D [5-8% solution of acetic acid in water]
Notes:
5-8% solution of acetic acid in water is called vinegar and is used widely as a preservative in pickles
8. Which of these methods is suitable to obtain the coloured component from black ink?
[A] Evaporation
[B] Sublimation
[C] Crystallisation
[D] All of the above
Show Answer
Correct Answer: A [Evaporation]
Notes:
The dye from water can be separated by the method of evaporation. Evaporation is used to separate the volatile component (solvent) from its non-volatile solute.
9. Which of the following is an endothermic reaction?
[A] Decomposition of calcium carbonate to calcium oxide and carbon dioxide
[B] Respiration
[C] Burning of Natural gas
[D] All of the above
Show Answer
Correct Answer: A [Decomposition of calcium carbonate to calcium oxide and carbon dioxide]
Notes:
Decomposition of calcium carbonate to calcium oxide and carbon dioxide is an endothermic reaction. Respiration and Burning of Natural gas are examples of exothermic reactions.
10. From which element in the modern periodic table, the 3d transition series starts?
[A] Zinc
[B] Iron
[C] Scandium
[D] Copper
Show Answer
Correct Answer: C [Scandium]
Notes:
The 3d transition series starts from scandium (Z = 21) and completes at zinc (Z=30). Reason for this transition series is that before the 4p orbital is filled, filling up of 3d orbitals becomes energetically favourable.
