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- Question 1 of 50
Which gas is used as a fire extinguisher?
Carbon dioxide (CO2) gas is used in a fire extinguisher because it displaces or reduces the amount of oxygen in the atmosphere around the fire. CO2 is suitable for both electrical and flammable liquid fire types.
- Question 2 of 50
Which one of the following is extensively used for sterilizing water?
Bleaching powder (CaOCl2) is extensively used for sterilizing water. The process of chlorination has been used for a long time to purify drinking water. Bleaching powder, in an aqueous solution, produces Cl– and OCl– ions. Whereas OCl– ion acts as a good bleaching agent by killing germs and bacteria.
- Question 3 of 50
Which mixture of gases is mainly stored as a liquid under pressure in LPG cylinder?
The mixture of Propane (C3H8) and Butane (C4H10) gases is mainly stored as a liquid under pressure in LPG cylinder.
- Question 4 of 50
The major constituent of air is:
The major constituent of air is Nitrogen (N2), which is about 78%. Oxygen (O2) is the second most abundant gas at about 21%. The inert gas Argon (Ar) is the third most abundant gas at 0.93%.
- Question 5 of 50
Which of the following organisms is most likely to produce greenhouse gases such as nitrous oxide and methane?
The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic). Bacteria are responsible for both the production and consumption of greenhouse gases such as carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4).
- Question 6 of 50
Rusting of iron takes place due to:
Rusting of iron takes place due to an oxidation reaction. The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust. Iron and steel rust when they come into contact with water and oxygen – both are needed for rusting to occur.
- Question 7 of 50
The highest grade and best equality coal is:
Anthracite is the highest grade and best equality coal. It is a hard, very low content of volatile compact variety of coal that has a high luster. It has the highest carbon content (92.1% to 98%), the fewest impurities, and the highest calorific content.
- Question 8 of 50
German silver used for making utensils is an alloy of:
German Silver is an alloy of copper (60%), zinc (20%) and nickel (20%). It is used for making daily utensils and jewellery.
- Question 9 of 50
The purity of gold is expressed in carats. The purest form of gold is:
The purity of gold is expressed in carats. 24 carat is pure gold with no other metals (100-percent gold and 0-percent other metals). Lower caratages contain less gold; 18-carat gold contains 75 percent gold and 25 percent other metals, often copper or silver.
- Question 10 of 50
Petroleum consists of a mixture of:
Petroleum consists of a mixture of Hydrocarbons. hydrocarbon is an organic compound composed only of the elements carbon (C) and hydrogen (H). There are four main categories of hydrocarbons Alkanes, Alkenes, Alkynes, and Aromatic hydrocarbons. Aromatic hydrocarbons are an important series of hydrocarbons found in almost every petroleum mixture.
- Question 11 of 50
The lustre of the metals is because of:
The lustre of the metals is because of the reflection of light due to the presence of free electrons. The free electrons can move freely in the metal causing any light incident on them to get reflected back.
- Question 12 of 50
Which One of the following is used to dissolve noble metals?
Aqua Regia (royal water) is used to dissolve noble metals. It is a mixture of nitric acid and hydrochloric acid in a ratio of 1:3. It can dissolve the noble metals gold and platinum, though not all metals.
- Question 13 of 50
An emulsion is a colloid of a:
An emulsion is a colloid of a liquid in a liquid. It is a mixture of two or more liquids that do not normally mix together.
- Question 14 of 50
The percentage of carbon in steel ranges from:
All steel contains at least some amount of carbon. After all, steel is defined as an alloy of iron and carbon. By adding carbon to it, the metal becomes stronger and harder. The percentage of carbon in steel ranges from 0.1 to 2. Depending on the carbon percentage, steel is classified into mild steel (0.02–0.05%), medium-carbon steel (0.05–1%) and high-carbon steel (1–2%).
- Question 15 of 50
Which of the following is not present in German Silver?
Silver is not present in German silver. German Silver is an alloy of copper (60%), zinc (20%) and nickel (20%). It is named for its silver-white colour. It is used for making daily utensils and jewellery.
- Question 16 of 50
The major harmful gas emitted by automobile vehicles which causes air pollution is:
Carbon monoxide (CO) is the major harmful gas emitted by automobile vehicles which causes air pollution. It results from incomplete combustion of fuel and is emitted directly from vehicle tailpipes.
- Question 17 of 50
Which one of the following is a major greenhouse gas?
Carbon dioxide is a major greenhouse gas. Earth’s greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic).
- Question 18 of 50
The chemical name of ‘Common salt’ is:
The chemical name of ‘Common salt’ is Sodium chloride. Sodium chloride is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium (Na+) and chloride (Cl–) ions.
- Question 19 of 50
Denatured spirit is ethanol mixed with:
Denatured spirit is ethanol mixed with Pyridine. It is ethanol that has additives to make it poisonous, bad-tasting, foul-smelling, or nauseating to discourage its recreational consumption.
- Question 20 of 50
The metal, which is a constituent of vitamin B12 is:
The metal, which is a constituent of vitamin B12 is Cobalt. Cyanocobalamin (commonly known as Vitamin B12) is a highly complex, essential vitamin, owing its name to the fact that it contains the mineral, cobalt.
- Question 21 of 50
The most abundant inert gas in the atmosphere is:
The most abundant inert gas in the atmosphere is Argon (Ar). The most abundant gas in the atmosphere is N2, which makes up about 78% of air. O2 is the second most abundant gas at about 21%. The inert gas Ar is the third most abundant gas at 0.93%. There are also trace amounts of CO2, Ne, He, CH4, Kr, H2, NO, Xe, O3, I2, CO, and NH3 in the atmosphere.
- Question 22 of 50
Which metal is extracted from seawater?
Magnesium is present in seawater in amounts of about 1300 ppm. The six most abundant ions of seawater are chloride (Cl−), sodium (Na+), sulfate (SO24−), magnesium (Mg2+), calcium (Ca2+), and potassium (K+). By weight, these ions make up about 99 percent of all sea salts.
- Question 23 of 50
Percentage of lead in lead pencils is:
Percentage of lead in lead pencils is 0. Lead pencils aren’t actually made from lead. It is made of a mixture of graphite and clay. Graphite is the part that makes the dark mark on the paper. The clay is there because graphite on its own is too soft to write.
- Question 24 of 50
Helium has is used in gas balloons instead of hydrogen gas because it is:
Flying balloons are filled with a gas lighter than the atmospheric air. Both hydrogen and helium are lighter than air. Hydrogen is even lighter than helium. Hydrogen, however, is not used in balloons because Helium (Noble Gas) is safe and non-reactive which means it is non-combustible.
- Question 25 of 50
The gas used in the artificial ripening of fruits is:
The gas used in the artificial ripening of fruits is Acetylene (C2H2). Calcium carbide (CaC2) is used for artificially ripening fruit. When calcium carbide comes in contact with moisture, it produces acetylene gas, which is similar in its effects to the natural ripening agent, ethylene. Note: ethylene (C2H4) is the natural ripening agent of plants.
- Question 26 of 50
Ruby and sapphire are oxides of:
Ruby and sapphire are precious gemstones, made of Aluminum Oxide (Al2O3) with trace amounts of elements such as iron, titanium, chromium, vanadium, or magnesium.
- Question 27 of 50
The gas which turns into liquid at the lowest temperature among the following is:
Condensation point is a temperature at which gas changes to liquid. Generally, boiling point is same as condensation point. The boiling and freezing points of helium are lower than those of any other known substance.
- Question 28 of 50
Gunpowder consists of a mixture of:
Gunpowder consists of a mixture of nitre (potassium nitrate), sulphur, and charcoal. Together, these materials will burn rapidly and explode as a propellant. The sulphur and charcoal act as fuels while the nitre is an oxidizer.
- Question 29 of 50
Which of the following is the sweetest sugar?
Fructose is the sweetest sugar. Sucrose is second sweetest followed by glucose and lactose.
- Question 30 of 50
In nuclear reactors, graphite is used as a/an:
The graphite bricks act as a moderator. They reduce the speed of neutrons and allow a nuclear reaction to be sustained.
- Question 31 of 50
The process involved in making soap is:
The process involved in making soap is saponification. Saponification is a process that involves the conversion of fat, oil, or lipid, into soap and alcohol by the action of aqueous alkali. Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. A typical soap is sodium oleate.
- Question 32 of 50
Seawater can be purified by the process of:
Seawater can be purified by the process of distillation. Distillation is a phase separation method whereby saline water is heated to produce water vapor, which is then condensed to produce fresh water.
- Question 33 of 50
The compound to which H2 does not add is:
The compound to which H2 does not add is Tetraphenyl ethylene (C26H20).
- Question 34 of 50
Ammonal is a mixture of:
Ammonal is an explosive made up of aluminium powder and ammonium nitrate. The mixture is often referred to as Tannerite, which is a brand of ammonal.
- Question 35 of 50
Which gas does not form the part of the atmosphere?
Chlorine gas is not part of the Earth’s atmosphere. Earth’s atmosphere is composed of about 78 percent nitrogen, 21 percent oxygen, 0.9 percent argon, and 0.1 percent other gases. Trace amounts of carbon dioxide, methane, water vapor, and neon are some of the other gases that make up the remaining 0.1 percent.
- Question 36 of 50
The fuel used in an atomic reactor is:
The fuel used in an atomic reactor is Uranium. Uranium is the most widely used fuel by nuclear power plants for nuclear fission.
- Question 37 of 50
The major constituent of gobar gas is:
Gobar gas (Biogas) contains mainly methane. It is a mixture of gases, primarily consisting of methane, carbon dioxide and hydrogen sulphide, produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste and food waste. It is a renewable energy source.
- Question 38 of 50
The isotope of Uranium used in atomic reactors is:
The isotope U235 is important because under certain conditions it can readily be split, yielding a lot of energy. It is therefore said to be ‘fissile’ and we use the expression ‘nuclear fission’.
- Question 39 of 50
Which one of the following is not a radioactive element?
Cadmium is not a radioactive element. Uranium, Thorium and Radium are radioactive elements.
- Question 40 of 50
The greenhouse effect is caused by the higher level of which gas in the atmosphere?
Earth’s greenhouse gases trap heat in the atmosphere and warm the planet. The main gases responsible for the greenhouse effect include carbon dioxide, methane, nitrous oxide, and water vapor (which all occur naturally), and fluorinated gases (which are synthetic).
- Question 41 of 50
Candle is a mixture of:
Candle is a mixture of Paraffin wax and stearic acid. Paraffin wax (CnH2n+2) is a white or colorless soft, solid wax. It’s made from saturated hydrocarbons. Stearic acid, another name for octadecanoic acid CH3(CH2)16COOH, is one of the most common fatty acids.
- Question 42 of 50
Ethanol containing 5 percent water is known as:
Ethanol containing 5 percent water is known as rectified spirit. Rectified spirit is a mixture of ethanol (95-96 percent) and water produced as an azeotrope by distillation.
- Question 43 of 50
Brass is an alloy of copper and:
Brass is a metal alloy primarily composed of copper and zinc. The composition of brass is generally 67% copper and 37% zinc. By varying the amount of copper and zinc, brass can be made harder or softer.
- Question 44 of 50
The density of a gas is maximum at:
The density of a gas is directly proportional to pressure and indirectly proportional to temperature. Thus, the density of a gas is maximum at low temperature and high pressure.
- Question 45 of 50
The important ore of aluminium is:
Bauxite is the most common aluminum ore. It is a sedimentary rock with a relatively high aluminium content. It is the world’s main source of aluminium (Al) and gallium (Ga).
- Question 46 of 50
Aqua regia is a 1:3 mixture, by volume, of:
Aqua regia (royal water) is a mixture of concentrated nitric and hydrochloric acids, usually one part of the former to three parts of the latter by volume. This mixture was given its name by the alchemists because of its ability to dissolve gold. It is a red or yellowish liquid.
- Question 47 of 50
What is the maximum Water Vapour content in the atmosphere?
The maximum water vapour content in the atmosphere is 3 to 4 percent. Temperature controls the amount of water in the atmosphere. The percentage of water vapor in the air ranges from 0.2 percent to 4 percent.
- Question 48 of 50
The amount of chlorine available in water after disinfection is called as:
The amount of chlorine available in water after disinfection is called as residual chlorine. Typically chlorine doses to final treated waters are in the range 0.2–2.0 mg/l of free chlorine to give a residual of about 0.02–0.3 mg/l at the consumer’s tap.
- Question 49 of 50
What are the major pollutants of cigarette smoke?
Major pollutants of cigarette smoke are Carbon monoxide (CO) and benzene (C6H6). Carbon monoxide is emitted in high concentrations in cigarette smoke. Benzene in cigarette smoke accounts for half of all human exposure to a cancer-causing toxin. Cigarette smoke includes carbon monoxide, hydrogen cyanide, benzene, formaldehyde, nicotine, etc.
- Question 50 of 50
Zinc sulphide is commonly used as:
The most common use of ZnS is as a rodenticide, pigment for paints, plastics, and rubber. The sulfides of zinc and of cadmium are the most important basic materials of sulfide-type phosphors.