Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. The Alkali metals are called good reducing agents. This implies that__:
[A] They easily capture electrons
[B] They are not stable at room temperature
[C] They easily lose electrons
[D] They don’t act with dilute acids
Show Answer
Correct Answer: C [They easily lose electrons ]
Notes:
Alkali metals have one electron in their valence shell and hence they easily lose or donate electron.
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. PVC is a polymer of__?
[A] Propane
[B] Vinyl chloride
[C] Styrene
[D] Carbonates
Show Answer
Correct Answer: B [Vinyl chloride]
Notes:
Polyvinyl chloride (PVC) is made from the monomer vinyl chloride (CH2 =CHCl). It is used for making raincoats, handbags, toys including dolls, electrical goods and as a covering of electrical wires.
4. Which among the following gases is used in production of Vanaspati ghee from vegetable oils?
[A] Nitrogen (N2)
[B] Carbon Dioxide (CO2)
[C] Hydrogen (H2)
[D] Neon (Ne)
Show Answer
Correct Answer: C [Hydrogen (H2)]
Notes:
Hydrogen (H2) gas is utilized in the manufacture of Vanaspati ghee from vegetable oils. The process involves hydrogenation, a chemical reaction between molecular hydrogen (H2) and another compound or element. Hydrogenation of vegetable oils helps to convert them into a semisolid form that resembles ghee, often used as a cheaper alternative to butter or ghee in cooking.
5. What is the electrical state of a molecule, considered the smallest part of matter retaining the properties of the original matter?
[A] Positive
[B] Negative
[C] Either positive or negative
[D] Neutral
Show Answer
Correct Answer: D [Neutral]
Notes:
A molecule represents the smallest portion of a substance that retains the characteristics of the substance. It’s electrically neutral because it’s made up of atoms that bond together, sharing or exchanging electrons to achieve stability. This process balances out the electrical charges of the protons and electrons, rendering the molecule as a whole electrically neutral.
6. Which of the following is not a common use of Graphite?
[A] Manufacturing of electrodes
[B] As a lubricant
[C] Manufacturing of crucibles
[D] In glass cutting
Show Answer
Correct Answer: D [In glass cutting]
Notes:
Graphite is renowned for its conspicuous uses owing to its unique properties like its ability to conduct electricity, which makes it ideal for electrode manufacturing. It’s also used as a lubricant and in the production of crucibles, thanks to its high melting point. However, it isn’t used in glass cutting.
7. Amalgam’ is a term used for an alloy of a metal with :
[A] Copper
[B] Mercury
[C] Lead
[D] Aluminium
Show Answer
Correct Answer: B [Mercury]
Notes:
The correct answer is Mercury. An amalgam is a specific type of alloy that primarily consists of mercury mixed with another metal, commonly used in dental fillings due to its durability and ease of use. Historically, amalgams have been used since ancient times, with the earliest known use dating back to the 9th century in China.
8. Which of the following alkali metal ions has the highest hydration enthalpy?
[A] Lithium
[B] Sodium
[C] Potassium
[D] Caesium
Show Answer
Correct Answer: A [Lithium]
Notes:
Lithium ions has maximum degree of hydration and for this reason lithium salts are mostly hydrated.
9. Which of the following compound of sodium is generally prepared by Solvay process?
[A] Sodium Carbonate
[B] Sodium Hydroxide
[C] Sodium Chloride
[D] All of the above
Show Answer
Correct Answer: A [Sodium Carbonate]
Notes:
Sodium carbonate is generally prepared by Solvay Process.
10. Which of the following elements is identified by the 7th group and 4th period of the modern periodic table?
[A] Copper
[B] Iron
[C] Manganese
[D] Chromium
Show Answer
Correct Answer: C [Manganese]
Notes:
Manganese is placed in the 7th group and 4th period of the modern periodic table. Its Atomic number is 25 and is placed group VII A.
