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. Which of the following is not a non-metallic mineral?
[A] Mica
[B] Bauxite
[C] Granite
[D] Silica
Show Answer
Correct Answer: B [Bauxite]
Notes:
Non-metallic minerals are those minerals which do not contain metals. Examples of Non-Metallic minerals include limestone, mica, coal, gypsum, dolomite, phosphate, salt, granite etc.
3. Which among the following is a common salt in Detergents?
[A] Sulphate
[B] Nitrate
[C] Sulphonate
[D] Carbonate
Show Answer
Correct Answer: A [Sulphate]
Notes:
Sodium sulfate, used as a filler in detergent powder, enables the adjustment of the concentration of the active matter in the detergent, as required.
4. Which among the following is the objective of the Methyl tert-butyl ether (MTBE) mixing with Petroleum?
[A] Raise Octane Number
[B] Antioxidant Stabilizer
[C] Lead Scavanger
[D] Fuel Dye
Show Answer
Correct Answer: A [Raise Octane Number ]
Notes:
MTBE is a gasoline additive, used as an oxygenate to raise the octane number. Its use is controversial in the US and declining in that country in part because of its occurrence in groundwater and legislation favoring ethanol.
5. What is the primary event that occurs during an oxidation reaction?
[A] Electrons are gained
[B] Electrons are lost
[C] Protons are gained
[D] Protons are lost
Show Answer
Correct Answer: B [Electrons are lost]
Notes:
Oxidation is a chemical reaction in which an atom, ion, or molecule loses an electron to another substance. So, the correct answer is “Electrons are lost”. This phenomenon is often observed in various chemical and biological systems. Understanding this important process can allow us to gain insights in fields ranging from biology to materials science.
6. What are Sodium Alkyl Sulphate and Benzene Sulphate examples of?
[A] Explosives
[B] Insecticides
[C] Fungicides
[D] Synthetic Detergents
Show Answer
Correct Answer: D [Synthetic Detergents]
Notes:
Sodium Alkyl Sulphate and Benzene Sulphate are typical examples of Synthetic Detergents. Synthetic detergents are man-made cleansing agents that function similarly to soap. These compounds were developed during World War II when a shortage of natural oils led to a search of alternative substances. The advanced features of synthetic detergents include improved cleansing efficacy, resistance to water hardness, and the ability to function in acidic conditions.
7. Which of the following elements is the most electronegative?
[A] Chlorine
[B] Fluorine
[C] Bromine
[D] All of them have the same electronegativity
Show Answer
Correct Answer: B [Fluorine]
Notes:
Electronegativity is defined as an atom’s ability to attract an electron pair when forming a covalent bond. This property increases as you move left to right across the periodic table due to an increase in the nuclear charge’s attractive forces. It decreases as you move top to bottom, owing to the shielding effect of sub-levels and increased atomic radius, which makes electrons easier to remove. This culminates in Fluorine, being the highest and furthest to the right on the periodic table, hence it is the most electronegative.
8. 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.
9. If a baby diaper is subjected to different solutions, which of the following will it absorb the maximum quantity of?
[A] Distilled Water
[B] Drinking Water
[C] Hard Water
[D] Urine
Show Answer
Correct Answer: A [Distilled Water]
Notes:
A baby diaper can absorb the maximum quantity of distilled water as it lacks impurities such as minerals and ions that are present in other type of water. The absorbent materials in diapers, often polymers called sodium polyacrylate, can hold up to 30 times their weight in distilled water, making them highly efficient.
10. Which among the following minerals is also known as Horn Silver?
[A] Silver Iodide
[B] Silver Chroride
[C] Zinc Phosphate
[D] Silver Sulphide
Show Answer
Correct Answer: B [Silver Chroride]
Notes:
Chlorargyrite is the mineral form of silver chloride (AgCl). It is also known as cerargyrite and, when weathered by desert air, as horn silver. Silver chloride is formed by the disappearance of the initial silver oxide layer.