Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. 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.
2. Which among the following methods can be used to remove the permanent hardness in water due to calcium or magnesium sulphates?
[A] Sulphonate method
[B] Nitrate method
[C] Zeolite method
[D] None of these
Show Answer
Correct Answer: C [Zeolite method ]
Notes:
Zeolite is hydrated Sodium Alumino-silicate capable of exchanging reversible Sodium ions for hardness producing ions in water. It is also use as softening of water. It is used to remove the permanent hardness in water due to Calcium or Magnesium sulphates.
3. “Atoms can neither be created nor destroyed.” This principle was given by __?
[A] Avogadro
[B] Dalton
[C] Rutherford
[D] Niels Bohr
Show Answer
Correct Answer: B [Dalton]
Notes:
The given principle is one of the postulates of the Dalton’s atomic theory given in 1803 by John Dalton. The postulates of Dalton’s atomic theory are as follows:
1. Elements consist of indivisible small particles (atoms).
2. All atoms of the same element are identical; different elements have different types of atom.
3. Atoms can neither be created nor destroyed.
4. ‘Compound elements’ (i.e. Compounds) are formed when atoms of different elements join in simple ratios to form ‘compound atoms’ (i.e. Molecules).
4. Which among the following is known as White Vitriol?
[A] Zinc Sulphate
[B] Zinc Chloride
[C] Zinc Phosphate
[D] Zinc oxide
Show Answer
Correct Answer: A [Zinc Sulphate]
Notes:
Zinc sulfate is the inorganic compound with the formula ZnSO4 and historically known as “white vitriol” Zinc sulfate is an inorganic compound and dietary supplement.
5. Trimethylxanthine is a chemical name of a stimulant which is found in tea and coffee. What is the popular name?
[A] Thein
[B] Caffeine
[C] Theobromine
[D] Theophylline
Show Answer
Correct Answer: B [Caffeine]
Notes:
Caffeine (1, 3, 7-trimethylxanthine) also known as ancient wonder drug is a basically a neurostimulant easily available all over the world and is used in different products like tea, coffee, analgesic adjuvant, soft drinks and many dietary supplements.
6. Ekaboron was an element predicted by Mendeleev and he leaved a space for it in his Periodic Table. Later Ekaboron was identified with _____?
[A] Gallium
[B] Scandium
[C] Technitium
[D] Germanium
Show Answer
Correct Answer: B [Scandium]
Notes:
Ekaboron was predicted by Dmitri Mendeleev in 1871, who left a space in his Periodic Table for it. It was later identified as Scandium (element 21) in 1879 by Lars Fredrik Nilson. Scandium shares similar properties with Ekaboron, aligning with Mendeleev’s predictions.
7. Which of the following laws is used as a rule to predict the solubility of gases in metals?
[A] Dalton’s Law
[B] Sievert’s law
[C] Graham’s law
[D] Henry’s law
Show Answer
Correct Answer: B [ Sievert’s law]
Notes:
Sievert’s law is used as a rule in physical metallurgy to predict the solubility of gases in metals.
8. 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.
9. Which of the following techniques can be used to separate cream from milk?
[A] Filtration
[B] Distillation
[C] Centrifugation
[D] Chromatography
Show Answer
Correct Answer: C [Centrifugation]
Notes:
Centrifugation is a mechanical process that utilizes an applied centrifugal force field to separate the components of a mixture.
10. Which of the following is the correct order of the decreasing order of abundance of the elements in earth’s crust?
[A] Iron > Silicon > Oxygen >Aluminium
[B] Oxygen > Silicon > Aluminium > Iron
[C] Oxygen> Iron > Aluminium > Silicon
[D] Iron > Aluminium > Silicon > Oxygen
Show Answer
Correct Answer: B [Oxygen > Silicon > Aluminium > Iron]
Notes:
Oxygen is the most abundant element in the earth’s crust followed by Silicon, Aluminium and Iron. It comprises almost half of the mass of the earth’s crust.
