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 is an alkaline earth metal?
[A] Pottasium
[B] Lead
[C] Copper
[D] Calcium
Show Answer
Correct Answer: D [Calcium ]
Notes:
The six elements in column 2 of the Periodic table are called Alkaline Earth Metals. These include Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).
2. 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).
3. Which among the following is correct ?
[A] Oxidation takes place at Cathode and Reduction Takes Place at Anode
[B] Oxidation takes place at Anode and Reduction Takes place at Cathode
[C] Both Oxidation and Reduction takes place at cathode
[D] Both Oxidation and Reduction takes place at Anode
Show Answer
Correct Answer: B [Oxidation takes place at Anode and Reduction Takes place at Cathode]
Notes:
In an electrochemical cell, the half cell where oxidation takes place is known as oxidation half cell and the half cell where reduction takes place is known as reduction half cell. Oxidation takes place at anode which is negatively charged and reduction takes place at cathode which is positively charged.
4. Which among the following is the main constituent of malleable metal alloy Pewter ?
[A] Copper
[B] Zinc
[C] Tin
[D] Bismuth
Show Answer
Correct Answer: C [Tin]
Notes:
Pewter is primarily composed of tin, typically around 85-95%, with the remainder often consisting of copper, antimony, or bismuth. Historically, pewter was used for making utensils and decorative items due to its malleability and low melting point. The use of tin in pewter dates back to ancient civilizations, including the Romans and Egyptians, who valued it for its corrosion resistance and ease of casting.
5. Water Gas is a mixture of?
[A] CO and H2
[B] CO and H2O
[C] CO2 and H2
[D] None of the Above
Show Answer
Correct Answer: A [CO and H2]
Notes:
The mixture of CO and H2 produced is known as water gas or synthesis gas.
6. What do we call the region of space around the nucleus where the probability of finding an electron is maximum?
[A] Shell
[B] sub-shell
[C] Orbital
[D] electron cloud
Show Answer
Correct Answer: C [Orbital]
Notes:
The region of space around the nucleus where the probability of finding an electron is maximum is called an orbital. The electron cloud is a visual model that represents all the orbitals in an atom
7. What is the half-life of Radium-223 isotope?
[A] 3 days
[B] 5 days
[C] 11.4 days
[D] 9.5 days
Show Answer
Correct Answer: C [11.4 days]
Notes:
The half-life of Radium-223 isotope is 11.4 days. The radium-226, which is a more common isotope of Radium and which wad discovered by the Curies, has a 1601-year half-life.
8. Which of the following factors affect the rate of chemical reaction?
[A] Concentration of reactants
[B] Temperature
[C] Catalyst
[D] All of the above
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Correct Answer: D [All of the above]
Notes:
The rate of reaction depends upon the experimental conditions such as concentration of reactants (pressure in case of gases), temperature and catalyst.
9. Which of the following is a part of chalcogen group of the modern periodic table?
[A] Boron
[B] Tin
[C] Lead
[D] Oxygen
Show Answer
Correct Answer: D [Oxygen]
Notes:
The chalcogens are the group 16 elements of the periodic table. This group is also known as the oxygen family. It consists of the elements oxygen (O), sulphur (S), selenium (Se), tellurium (Te), and the radioactive element polonium (Po).
10. What do we call the number of water molecules present in one formula unit of a salt?
[A] Formula number of salt
[B] Power of the salt
[C] Water of crystallisation
[D] Hydro number
Show Answer
Correct Answer: C [Water of crystallisation]
Notes:
The fixed number of water molecules present in one formula unit of a salt is called water of crystallisation. For example, one formula unit of copper sulphate has five molecules of water in it.
