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 is the correct decreasing of bio elements in Human Body?
[A] oxygen, hydrogen, Carbon, nitrogen, calcium, and phosphorus
[B] oxygen, carbon, nitrogen, hydrogen, calcium, and phosphorus
[C] oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus
[D] carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorus
Show Answer
Correct Answer: C [oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus ]
Notes:
In the human body the most common bio-elements (in decreasing order of occurrence) are oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Other bio-elements include sodium, potassium, magnesium, and copper.
2. 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.
3. Which colour does cobalt oxide impart to glass?
[A] Brown
[B] Blue
[C] Red
[D] Yellow
Show Answer
Correct Answer: B [Blue]
Notes:
Cobalt Oxide is commonly used to create a distinctive blue hue in glasses and ceramics. The depth of the blue can be altered by changing the concentration of the oxide. In addition to being used for aesthetic purposes, Cobalt blue, which results from Cobalt Oxide, is also used because it absorbs certain wavelengths of light, making it useful for filtering out unwanted wavelengths.
4. How many parts are of other metals in a 17 carat Gold?
[A] 3
[B] 5
[C] 7
[D] 9
Show Answer
Correct Answer: C [7]
Notes:
In 17 carat gold, the composition is 17 parts gold and 7 parts other metals, making it 70.6% gold. The term “carat” refers to the purity of gold, with 24 carats being pure gold. Thus, 17 carat gold contains 7 parts of other metals, which can include copper, silver, or palladium, used to enhance durability and alter color.
5. Gammaxene, D.D.T. and Bleaching powder are important compounds of :
[A] Chlorine
[B] Nitrogen
[C] Sulphur
[D] Phosphorus
Show Answer
Correct Answer: A [Chlorine]
Notes:
The correct answer is Chlorine. – Gammaxene (also known as Lindane) is a pesticide derived from hexachlorocyclohexane, which involves chlorine. – D.D.T. (Dichloro-Diphenyl-Trichloroethane) is a synthetic pesticide containing chlorine. – Bleaching powder (calcium hypochlorite) is a chlorine compound used for disinfection and bleaching. Chlorine is essential in various chemical processes and compounds, particularly in agriculture and sanitation.
6. What happens to the non-metallic character of elements in the p-block of the periodic table?
[A] non-metallic character decreases down the group
[B] non-metallic character increases down the group
[C] No fix pattern
[D] None
Show Answer
Correct Answer: A [non-metallic character decreases down the group]
Notes:
The non-metallic character of elements decreases down the group. In fact, the heaviest element in each p-block group is the most metallic in nature.
7. Which of the following is incorrect?
[A] Alloying helps in improving the properties of a metal
[B] An alloy is a heterogeneous mixture of two or more metals
[C] The melting point of an alloy is less than that of pure metals
[D] All of the above
Show Answer
Correct Answer: B [An alloy is a heterogeneous mixture of two or more metals]
Notes:
An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. Alloying helps in improving the properties of a metal. The melting point of an alloy is less than that of pure metals.
8. Which of the following metals is extracted and refined in the Mond’s process?
[A] Cobalt
[B] Bismuth
[C] Nickel
[D] Copper
Show Answer
Correct Answer: C [Nickel]
Notes:
The Mond process is a technique to extract and purify nickel. It is also known as the carbonyl process. In this, nickel is heated in a stream of carbon monoxide forming a volatile complex, nickel tetracarbonyl.
9. Which of the following methods is used to purify Titanium metal?
[A] Hall-Heroult process
[B] van Arkel method
[C] Mond process
[D] None of the above
Show Answer
Correct Answer: B [van Arkel method]
Notes:
van Arkel method is used for refining Titanium: This method is very useful for removing all the oxygen and nitrogen present in the form of impurity in Titanium.
10. Who correctly discovered or calculated for subatomic particles?
[A] John Dalton discovered electrons
[B] James Chadwick discovered protons
[C] Rutherford calculated charge to mass ratio of electrons
[D] None of the above
Show Answer
Correct Answer: D [None of the above]
Notes:
J.J. Thomson discovered electrons in 1897. Ernest Rutherford discovered protons in 1917. J.J. Thomson calculated the charge to mass ratio of electrons in 1897. James Chadwick discovered neutrons in 1932. John Dalton proposed the atomic theory in 1808 but did not discover electrons or protons.
