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 of the following does not increase when we move from left to right along a period in the periodic table?
[A] Oxidising Power of elements
[B] Electronegativity
[C] Non-metallic Character
[D] Reducing power
Show Answer
Correct Answer: D [Reducing power]
Notes:
The oxidizing power of elements increases on moving left to right along a period in the periodic table. This is because electronegativity and the non-metallic character increases from left to right.
2. 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.
3. Which among the following acids is abundant in Grapes, Bananas and Tamarind?
[A] Lactic Acid
[B] Oxalic Acid
[C] Salicylic Acid
[D] Tartaric Acid
Show Answer
Correct Answer: D [Tartaric Acid ]
Notes:
Tartaric acid occurs naturally in many fruits such as grapes, bananas, tamarinds, and citrus. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally in the process of winemaking. It is commonly mixed with sodium bicarbonate and is sold as baking powder used as a leavening agent in food preparation. The acid itself is added to foods as an antioxidant E334 and to impart its distinctive sour taste.
4. Which of the following is a thermosetting plastic?
[A] Polythene
[B] Bakelite
[C] Polyvinyl chloride
[D] Casseine
Show Answer
Correct Answer: B [Bakelite]
Notes:
Bakelite is a thermosetting plastic formed from phenol and formaldehyde, used in electrical insulators and cookware handles. Unlike thermoplastics, it hardens irreversibly when heated and cannot be remolded. It was the first synthetic plastic, invented by Leo Baekeland in 1907.
5. Cassiterite is a primary ore of which of the following elements?
[A] Iron
[B] Zinc
[C] Copper
[D] Tin
Show Answer
Correct Answer: D [Tin]
Notes:
Cassiterite is a mineral that is a significant ore of tin. It is also known as tin oxide. Although rare, its key characteristic is its high specific gravity that makes it easy to separate it from other materials. Tin, which is extracted from Cassiterite, is commonly used in making alloys, punches, and cutting tools.
6. Which among the following gas is used in Balloons?
[A] Hydrogen
[B] Helium
[C] Nitrogen
[D] Oxygen
Show Answer
Correct Answer: B [Helium]
Notes:
The correct answer is Helium. Helium is a non-flammable, lighter-than-air gas, making it safe for use in balloons. Unlike hydrogen, which is highly flammable and poses explosion risks, helium is inert and does not react with other substances. Helium is the second most abundant element in the universe, primarily produced through nuclear fusion in stars. It was first discovered in the sun before being found on Earth.
7. What is the nature of an aqueous solution of Sodium Acetate?
[A] Acidic
[B] Basic
[C] Neutral
[D] Either acidic or basic, depending on the temperature of the solution
Show Answer
Correct Answer: B [Basic]
Notes:
An aqueous solution of sodium acetate is basic in nature. This is because sodium acetate is a salt derived from a strong base (sodium hydroxide) and a weak acid (acetic acid). When dissolved in water, it undergoes hydrolysis to form sodium ions and acetate ions. The acetate ions react with water to form acetic acid and hydroxide ions, thus creating a basic solution.
8. Which among the following alkane has largely replaced the ozone layer-depleting halomethanes in household refrigerators and freezers?
[A] Methane
[B] Propane
[C] Butane
[D] Ethane
Show Answer
Correct Answer: C [Butane]
Notes:
Isobutane, which is known in the industry as R600A has been used in several domestic refrigerators in recent times because it is an excellent refrigerant and non-ozone depleting substance with low global warming potential. The only drawback is that it is highly inflammable.
9. Ilmenite, found in Indian coastal sands, is an ore of which element?
[A] Tungsten
[B] Titanium
[C] Gallium
[D] Tin
Show Answer
Correct Answer: B [Titanium]
Notes:
Ilmenite is a titanium-iron oxide mineral with the formula FeTiO3. India holds about 37% of global ilmenite reserves, primarily along the peninsular coastal regions. Ilmenite is the primary source of titanium, used in aerospace, chemical, and medical industries. The Geological Survey of India ranks ilmenite among the most abundant heavy minerals in Indian beach placers. Titanium extraction from ilmenite is commercially viable.
10. Which of the following chemicals is resposible for temporary acid rain in colder regions?
[A] Hydrogen chloride
[B] Sulphur dioxide
[C] Nitric acid
[D] Nitrogen oxides
Show Answer
Correct Answer: A [ Hydrogen chloride]
Notes:
Hydrogen chloride gas released from volcanic eruption is responsible for temporary acid rain in colder regions.