Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination.
1. The Helium atoms that have lost two electrons are called ________?
[A] Alpha rays
[B] Beta rays
[C] Gamma rays
[D] None of the above
Show Answer
Correct Answer: A [Alpha rays]
Notes:
Helium atoms that have lost two electrons are called alpha rays. Alpha rays are also called alpha particles or alpha radiation. Alpha particles are made up of two protons and two neutrons bound together into a particle that is identical to a helium-4 nucleus.
Alpha particles are named after the first letter in the Greek alphabet, α. They were the first nuclear radiation to be discovered.
When a helium atom loses its electrons, it is left with only the nucleus. This is called an alpha particle.
2. In the E-waste generated by the Mobile Phones, which among the following metal is most abundant?
[A] Copper
[B] Silver
[C] Palladium
[D] Gold
Show Answer
Correct Answer: A [Copper]
Notes:
The sources of e-waste are faulty desktop computers, cables, printers, refrigerators, air conditioners, televisions, electronic and electrical devices. E-waste generated by the Mobile Phones are copper, silver, gold, palladium. Among them copper is found abundantly.
3. L.P.G. is a hydrocarbon consisting of a mixture of :
[A] Methane and Butane
[B] Propane and Butane
[C] Ethane and Propane
[D] Ethane and Butane
Show Answer
Correct Answer: B [Propane and Butane]
Notes:
L.P.G. (Liquefied Petroleum Gas) primarily consists of propane and butane. It is used as fuel for heating, cooking, and vehicles. Propane (C3H8) and butane (C4H10) are both byproducts of natural gas processing and petroleum refining. LPG is favored for its high energy content and clean-burning properties.
4. Which among the following compound is most commonly used in the Photochromic lenses?
[A] Potassium Dichromate
[B] Silver Chloride
[C] Potassium ferrate
[D] Ferric Chloride
Show Answer
Correct Answer: B [ Silver Chloride]
Notes:
Silver halides and most commonly silver Chloride is used in Photochromic lens. But for plastic photochromic lenses, some organic products such as oxazines and naphthopyrans are used.
5. 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.
6. If we take 1 kg of iron and let it rust, and none of the rust falls off, then the total weight will be___?
[A] Less than 1 Kg
[B] More than 1 Kg
[C] Exact 1 Kg
[D] More or Less than 1 Kg
Show Answer
Correct Answer: B [More than 1 Kg]
Notes:
If the rust stays attached to the main body or the flakes of rust that fall off are collected and weighed than the weight will increase. If you are using for example iron shavings than the chemical formula would look like this Fe(II) + O2 = FeO2 And the weight will increase by the mass of the shavings divided by the molar mass of iron times 2 times the molar mass of oxygen (in this case taking the molar mass of oxygen as a single oxygen atom not a pair). Thus, When rust forms, the mass of the iron object is increased by the mass of oxygen that has combined with some of the iron
7. Which of the following is not a mixture?
[A] Ocean water
[B] Table salt
[C] Air
[D] Soil
Show Answer
Correct Answer: B [Table salt]
Notes:
The composition of a mixture is variable whereas it is fixed for a compound. Table salt i.e. Sodium chloride is a compound and not a mixture.
8. Which of the following is an example of colloidal solution?
[A] Milk
[B] Fog
[C] Smoke
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Milk, Fog, Smoke, Cheese, Clouds, Mist, Shaving cream, Butter, Jelly etc. are some of the examples of colloidal solution.
9. What do we call the process of converting an ore into its oxide by heating it in a limited supply of air below its melting point?
[A] Roasting
[B] Calcination
[C] Leaching
[D] Liquation
Show Answer
Correct Answer: B [Calcination]
Notes:
Calcination is the process of converting an ore into its oxide by heating it in a limited supply of air or in absence of air, below its melting point. It is used to convert the concentrated ore to its oxide.
10. Which of the following refining methods works on the principle of adsorbtion?
[A] Zone refining
[B] Vapour Phase refining
[C] Chromatographic methods
[D] Liquation
Show Answer
Correct Answer: C [Chromatographic methods]
Notes:
Chromatographic methods are based on the principle that different components of a mixture are differently adsorbed on an adsorbent. There are several chromatographic techniques used for refining such as paper chromatography, column chromatography, gas chromatography, etc
These questions are part of GKToday's 40,000+ GK Questions Course in GKToday Android Application which provides more than 40K questions with explanations suitable for all Competitive Exams of India.