Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. Who among the following scientists had discovered Radium?
[A] Marie Sklodowska-Curie and Pierre Curie
[B] André-Louis Debierne
[C] Kasimir Fajans
[D] Oswald Helmuth Göhring
Show Answer
Correct Answer: A [Marie Sklodowska-Curie and Pierre Curie ]
Notes:
Radium is a chemical element with the symbol Ra and atomic number 88. Radium was discovered by Marie Sklodowska Curie, a Polish chemist, and Pierre Curie, a French chemist, in 1898.
2. Which of the following is the use of washing soda?
[A] softening of water
[B] manufacture of glass
[C] manufacture of paints
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
It is used for softening of water, laundering, cleaning, manufacture of glass, soap, borax, paper, paints and textile It is also extensively used as laboratory reagent.
3. Which of the following element is NOT an alkaline earth metal?
[A] Magnesium
[B] Strontium
[C] Barium
[D] Beryllium
Show Answer
Correct Answer: D [Beryllium]
Notes:
The elements of Group 2 include beryllium, magnesium, calcium, strontium, barium and radium. These elements with the exception of beryllium are commonly known as the alkaline earth metals.
4. Which of the following metal is the main constituent in Pewter alloy?
[A] Lead
[B] Zinc
[C] Tin
[D] Iron
Show Answer
Correct Answer: C [Tin]
Notes:
The term pewter covers a variety of alloys consisting primarily of tin. It is composed of 85–99% tin, mixed with copper, antimony, bismuth, silver or lead..
5. 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.
6. Hydraulic Washing:
- is used for concentration of ores
- is based on differences in magnetic properties of the ore components
Which of the above is / are correct?
[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: A [Only 1 ]
Notes:
Hydraulic Washing is a method used for concentration of ores. It is a type of gravity separation as it is based on the differences in gravities of the ore and the gangue particles.
7. Which of the following is the correct order in terms of Iron content?
[A] Magnetite > Haematite >Siderite > Limonite
[B] Haematite> Magnetite >Siderite > Limonite
[C] Haematite > Magnetite > Limonite > Siderite
[D] Magnetite > Haematite > Limonite > Siderite
Show Answer
Correct Answer: D [Magnetite > Haematite > Limonite > Siderite]
Notes:
Magnetite > Haemetite > Limonite > Siderite . Magnetite has 72.4% iron content. Haematite has 70% iron content. Limonite has 55% iron content. Siderite has 48.2% iron content.
8. Which of the following quantum number is also known as orbital angular momentum?
[A] Principal quantum number
[B] Azimuthal quantum number
[C] Magnetic quantum number
[D] Electron spin quantum number
Show Answer
Correct Answer: B [Azimuthal quantum number]
Notes:
Azimuthal quantum number is also known as orbital angular momentum or subsidiary quantum number. It is represented by ‘l’.
9. Which of the following is true about Rutherford model of atom?
[A] it explains how the electrons are distributed around the nucleus
[B] It cannot explain about the stability of an atom around the nucleus
[C] It tells us about the energies of the electrons around the nucleus
[D] All of the above
Show Answer
Correct Answer: B [It cannot explain about the stability of an atom around the nucleus]
Notes:
A serious limitation of the Rutherford model is that it says nothing about the electronic structure of atoms i.e., how the electrons are distributed around the nucleus and what are the energies of these electrons. Also, the Rutherford model cannot explain the stability of an atom.
10. What is the relationship between becquerel and curie unit?
[A] 1 curie = 0.5 Bq
[B] 1 curie = 9 × 106 Bq
[C] 1 curie = 3.7 × 1010 Bq
[D] 1 curie = 5.7 Bq
Show Answer
Correct Answer: C [1 curie = 3.7 × 1010 Bq]
Notes:
1 curie = 1 Ci = 3.7 × 1010 decays per second = 3.7 × 1010 Bq. This is approximately the amount of radioactivity emitted by one gram (1 g) of radium-226. The ‘curie’ unit is named after Pierre Curie, a French physicist.
