Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. What is the key element used in the batteries of electric vehicles?
[A] Magnesium
[B] Lithium
[C] Sodium
[D] Bromine
Show Answer
Correct Answer: B [Lithium]
Notes:
The primary component for electric vehicle batteries is Lithium, used as Lithium carbonate or Lithium hydroxide. These Lithium-ion batteries have a high power-to-weight ratio, energy efficiency, and thermal stability, leading to their prevalence in electric vehicles. Notably, the boom in EVs has significantly driven the demand for Lithium globally.
2. Dalton’s name is associated with which of the following terms?
[A] Electron
[B] Proton
[C] Atom
[D] Neutron
Show Answer
Correct Answer: C [Atom]
Notes:
John Dalton introduced the atomic theory into chemistry. The main points of Dalton’s atomic theory are (1) Elements are made of extremely small particles called atoms. (2) Atoms of a given element are identical in size, mass and other properties; atoms of different elements differ in size, mass and other properties.(3) Atoms cannot be subdivided, created or destroyed. (4) Atoms of different elements combine in simple whole-number ratios to form chemical compounds. (5) In chemical reactions, atoms are combined, separated or rearranged.
3. Which among the following groups is characteristic to alcohols?
[A] OH group
[B] COOH group
[C] COO group
[D] CO group
Show Answer
Correct Answer: A [OH group]
Notes:
Alcohols are organic compounds characterized by the presence of a hydroxyl group, denoted as -OH. This group consists of one oxygen atom bonded to a hydrogen atom. Due to the presence of the hydroxyl group, alcohols exhibit unique properties, such as the ability to form hydrogen bonds, making them polar. Alcohols are distinct from carboxylic acids (COOH), carbonates (COO), and carbonyl group compounds (CO).
4. Which among the following compound of barium is used as radio contrast agent for X-ray imaging and other diagnostic procedures and also commonly called as Barium Food?
[A] Barium Carbonate
[B] Barium Sulphate
[C] Barium Bromide
[D] Barium hydroxide
Show Answer
Correct Answer: B [Barium Sulphate]
Notes:
Barium Sulphate is the correct answer. It is used as a radiopaque contrast agent in X-ray imaging because it absorbs X-rays, making it visible on the images. Commonly referred to as “Barium Meal” when ingested for gastrointestinal studies, it helps diagnose conditions like ulcers and tumors. Barium Sulphate is insoluble in water, ensuring it remains in the digestive tract without being absorbed.
5. 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.
6. Which of the following statements is incorrect about Stainless Steel?
[A] it is also known as inox steel
[B] It is an alloy of Iron, cobalt and nickel
[C] It is corrosion resistant
[D] molybdenum is added to increase corrosion resistance in reducing acids
Show Answer
Correct Answer: B [It is an alloy of Iron, cobalt and nickel]
Notes:
Stainless steel is also known as inox steel. It is an alloy of Iron, chromium and nickel. It is corrosion resistant and molybdenum is added to increase corrosion resistance in reducing acids.
7. Which of the following does not represent the Atomic number of an atom?
[A] number of protons in the nucleus of an atom
[B] number of electrons in a neutral atom
[C] number of neutrons in the nucleus of an atom
[D] None of the above
Show Answer
Correct Answer: C [number of neutrons in the nucleus of an atom]
Notes:
The number of protons present in the nucleus of an atom or the number of electrons in a neutral atom is equal to its atomic number. It is represented by Z.
8. What is the S.I unit of activity?
[A] becquerel
[B] curie
[C] candela
[D] henry
Show Answer
Correct Answer: A [becquerel]
Notes:
The SI unit for activity is becquerel, named after the discoverer of radioactivity, Henry Becquerel. The c.g.s unit of activity is curie.
9. What is the period and group number of Silicon (Z=14) in the periodic table?
[A] 2nd Period, 4th Group number
[B] 2nd Period, 14th Group number
[C] 3rd Period, 4th Group number
[D] 3rd Period, 14th Group number
Show Answer
Correct Answer: D [3rd Period, 14th Group number]
Notes:
Silicon has an atomic number 14 and the outer electronic configuration is 3s2 3ps2. It is placed at the 3rd Period and 14th Group number.
10. What is the reason for the increase in the electronegativity across a period from left to right?
[A] attraction between the valence electrons and the nucleus increases
[B] attraction between the valence electrons and the nucleus decreases
[C] increase in the atomic weight
[D] None of the above
Show Answer
Correct Answer: A [attraction between the valence electrons and the nucleus increases]
Notes:
The attraction between the outer (or valence) electrons and the nucleus increases as the atomic radius decreases in a period. The electronegativity also increases.
