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 substances is most suitable for making Compact Discs?
[A] PVC
[B] Polyethylene
[C] Polyamides
[D] Polycarbonates
Show Answer
Correct Answer: D [Polycarbonates
]
Notes:
Polycarbonate(PC) is a tough thermoplastic. It is not only highly transparent but also has good toughness which most of the other thermoplastics do not possess. For this reason, it is widely used for making CDs, Safety Goggles, Mixer jar lids etc.
2. Which among the following is an ionic solid?
[A] Diamond
[B] Dry ice
[C] Table salt
[D] All are ionic solids
Show Answer
Correct Answer: C [Table salt]
Notes:
One important character of Ionic solids is that they readily get dissolved in water
3. 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.
4. Which of the following elements have the lowest and highest boiling point in the Periodic table?
[A] Helium and Tungsten
[B] Hydrogen and Rhenium
[C] Helium and Rhenium
[D] Hydrogen and Tungsten
Show Answer
Correct Answer: C [ Helium and Rhenium]
Notes:
Helium has the lowest boiling point of all the elements at –452.074°F (–268.93°C) followed by hydrogen –423.16°F (–252.87°C). The highest boiling point for an element is that of Rhenium 10,104.8°F (5,596°C) followed by tungsten 10,031°F (5,555°C).
5. Which among the following impurity in drinking water causes the “Bamboo Spine” disorder?
[A] Nitrate
[B] Fluorides
[C] Arsenic
[D] Sulphides
Show Answer
Correct Answer: B [ Fluorides]
Notes:
Ankylosing Spondylitis is a chronic, inflammatory arthritis and autoimmune disease that mainly affects joints in the spine and the sacroiliac joints in the pelvis. It tends to affect the spine and in late stages, the spine will fuse and this has given rise to the term “bamboo spine”. It is mainly caused due to impurities in drinking water associated with fluorides.
6. How many electrons can the s-orbital accommodate?
[A] 1
[B] 2
[C] 8
[D] 16
Show Answer
Correct Answer: B [2]
Notes:
A the s-orbital can accommodate only two electrons, two groups (1 & 2) belong to the s-block of the Periodic Table.
7. Bell metal is an alloy of which of the following metals?
[A] Copper and Tin
[B] Copper and Mercury
[C] Copper and Lead
[D] Copper and Zinc
Show Answer
Correct Answer: A [Copper and Tin]
Notes:
Bell metal is a form of bronze with a higher tin content. It is an alloy of copper and tin (typically, 78% copper, 22% tin by mass). It is used for making bells and related instruments, such as cymbals.
8. In which of the following cases, components can be separated using a separating funnel?
[A] Mixture of acetone and water
[B] Mixture of oil and water
[C] Different gases in the air
[D] None of the above
Show Answer
Correct Answer: B [Mixture of oil and water]
Notes:
A separating funnel can be used to separate the components of the mixture of immiscible liquids. Components in the mixture of oil and water can be separated using this method.
9. Which of the following quantum numbers is not necessary to identify an orbital?
[A] Principal quantum number
[B] Azimuthal quantum number
[C] Magnetic quantum number
[D] Electron Spin quantum number
Show Answer
Correct Answer: D [Electron Spin quantum number]
Notes:
An orbital is identified by the set of 3 quantum numbers: Principal quantum number, Azimuthal quantum number and magnetic quantum number.
10. Which of the following decays represents the decay of Uranium-238 to thorium-234?
[A] Alpha decay
[B] Beta decay
[C] Gamma decay
[D] None of the above
Show Answer
Correct Answer: A [Alpha decay]
Notes:
The radioactive decay of uranium-238 to thorium-234, with the emission of a helium nucleus, is a well-known example of alpha decay.
