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 is popularly called Hypo?
[A] Silver Bromide
[B] Silver nitrate
[C] Sodium thiosulphate
[D] Sodium phosphate
Show Answer
Correct Answer: C [Sodium thiosulphate ]
Notes:
Sodium thiosulfate is an important inorganic salt with several medical uses. It is also called sodium hyposulfite or ‘hypo’. It is used in several pharmaceutical preparations and also has various medical properties.
2. Potassium permanganate is used to purify water. Which among the following properties of Potassium permanganate helps in this work?
[A] sterilizing
[B] oxidizing
[C] reducing
[D] leaching
Show Answer
Correct Answer: B [oxidizing]
Notes:
Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.
3. Which of the following is the correct term used to describe Graphite, Carbon and Diamonds?
[A] Isotopes
[B] Isomers
[C] Isotones
[D] Allotropes
Show Answer
Correct Answer: D [Allotropes]
Notes:
Allotropes refer to two or more different physical forms in which an element can exist. The property is due to different ways atoms bond together. The most common instance is the element carbon, which exists in several different forms, including diamond, graphite, and fullerenes, making it an allotropic element. It’s crucial to note that allotropy applies to elements, not compounds.
4. What is the primary use of Phenolphthalein in chemistry?
[A] A Solvent
[B] A Dye
[C] A Catalyst
[D] A Detergent
Show Answer
Correct Answer: B [A Dye]
Notes:
Phenolphthalein is commonly employed as a pH indicator in titrations due to its distinct color change in varying pH levels. At pH 8.2, it appears colorless but turns pink as the pH increases to 10. It is not used as a solvent, catalyst or detergent. It also finds applications in forensic science for detecting latent blood stains.
5. According to Avogadro’s hypothesis, equal volumes of gases contain equal number of?
[A] Atoms
[B] Molecules
[C] Particles
[D] Electrons
Show Answer
Correct Answer: B [Molecules]
Notes:
Avogadro’s hypothesis was proposed by Amedeo Avogadro in 1811. It states that equal volumes of all gases, at the same temperature and pressure, contain equal numbers of molecules. Avogadro’s number is defined as 6.022×10^23 molecules per mole. This hypothesis was crucial for determining molecular weights and led to the development of the ideal gas law.
6. Hard Water contains which of the following ?
[A] Aluminum
[B] Chlorine
[C] Calcium
[D] Zinc
Show Answer
Correct Answer: C [Calcium]
Notes:
Hard water is generally found in areas where groundwater is in contact with limestone, chalk and dolomite and gets higher amount of calcium and magnesium dissolved in it.
7. Kazimierz Funk or Casimir Funk, was a Polish biochemist, generally credited with the first formulation of the concept of which of the following ?
[A] Amino Acids
[B] DNA
[C] RNA
[D] Vitamins
Show Answer
Correct Answer: D [Vitamins]
Notes:
Kazimierz Funk (1884 – 1967) was a Polish biochemist, and one of the first to formulate the concept of Vitamins.
8. Which of the following is the most common naturally occurring form in which silicon is found?
[A] Oxide
[B] Fluoride
[C] Nitride
[D] Sulphide
Show Answer
Correct Answer: A [ Oxide ]
Notes:
Silica is also known as Silicon dioxide, is the most prevalent form of naturally occurring silicon.
9. 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.
10. Which of the following is correct about Ammonia?
[A] The ammonia molecule is trigonal pyramidal in shape
[B] Ammonia gas is light blue in colour
[C] its aqueous solution is highly basic
[D] Ammonia gas is odorless
Show Answer
Correct Answer: A [The ammonia molecule is trigonal pyramidal in shape]
Notes:
Ammonia is a colourless gas with a pungent odour. Its aqueous solution is weakly basic due to the formation of OH– ions. The ammonia molecule is trigonal pyramidal in shape.
