Which metal does not form an amalgam? a) Zinc b) Copper c) Magnesium d) Iron Answer: d
Besides carbon monoxide, which of the following gases is also highly flammable? a) Helium b) Nitrogen c) Oxygen d) Hydrogen Answer: d
Which substance causes permanent hardness of water? a) Magnesium bicarbonate b) Sodium chloride c) Calcium sulphate d) Calcium bicarbonate Answer: c
The chemical name of common salt is: a) Sodium chloride b) Sodium nitrate c) Ammonium chloride d) Calcium chloride Answer: a
Brass is an alloy made of: a) Copper and Zinc b) Copper and Tin c) Copper and Silver d) Copper and Nickel Answer: a
Sodium carbonate is commonly known as: a) Baking soda b) Washing soda c) Caustic soda d) Bleaching soda Answer: b
Heating ore below its melting point in the absence of air is called: a) Roasting b) Smelting c) Refining d) Calcination Answer: d
The common name of sodium bicarbonate is: a) Baking soda b) Borax c) Bleach d) Epsom salt Answer: a
Which of the following contains the highest percentage of carbon? a) Cast iron b) Stainless steel c) Wrought iron d) High-speed steel Answer: a
Lime mortar is a mixture of water, sand, and: a) Slaked lime b) Quick lime c) Limestone d) Gypsum Answer: a
The ability of metals to be drawn into wires is called: a) Malleability b) Viscosity c) Ductility d) Tensile strength Answer: c
Why is helium used in balloons instead of hydrogen? a) It is lighter than hydrogen b) It is more abundant c) It is non-combustible d) It is more stable Answer: c
What is formed when magnesium oxide reacts with water? a) Mg(OH) b) Mg₂(OH) c) Mg(O₂H)₂ d) Mg(OH)₂ Answer: d
A helium-filled balloon rises in air because: a) Air pushes it upward b) It is weightless c) Helium is less dense than air d) Helium pushes the air down Answer: c
Magnesium reacts with oxygen to form: a) Mg₂O b) MgO c) O₂Mg d) MgO Answer: b
Which noble gas is capable of forming compounds? a) Helium b) Argon c) Xenon d) Krypton Answer: c
Which of the following is an inert gas? a) Hydrogen b) Nitrogen c) Oxygen d) Argon Answer: d
White phosphorus is stored under: a) Ammonia b) Cold water c) Alcohol d) Kerosene Answer: b
Which of the following is NOT a property of metals? a) Hardness b) Lustre c) Malleability d) Poor heat conductivity Answer: d
Which gas is used as an anesthetic? a) NH₃ b) NO c) NO₂ d) N₂O Answer: d
Which of the following metals is the heaviest? a) Iron b) Silver c) Nickel d) Osmium Answer: d
The number of unpaired electrons in inert gases is: a) 0 b) 8 c) 4 d) 18 Answer: a
Which of the following elements has the lowest melting point? a) Iodine b) Lead c) Tin d) Mercury Answer: d
Old oil paintings blacken due to the formation of: a) Cu₂S b) PbS c) CaS d) Na₂S Answer: b
The most effective adsorbent among the following is: a) Charcoal b) Activated charcoal c) Activated coconut charcoal d) Carbon black Answer: c
Asbestos is chemically: a) Calcium magnesium silicate b) Alumina c) Calcium silicate d) Magnesium silicate Answer: a
Which form of coal has the highest carbon content? a) Anthracite b) Bituminous c) Peat d) Lignite Answer: a
If a bullet remains lodged in the body, it may cause poisoning due to: a) Mercury b) Lead c) Iron d) Arsenic Answer: b
The most important raw material for power generation in India is: a) Mineral oil b) Natural gas c) Uranium d) Coal Answer: d
The purest form of gold is: a) 24 carat b) 99.6 carat c) 91.6 carat d) 22 carat Answer: a
Inert gases are: a) Miscible with water b) Unstable c) Chemically unreactive d) Highly reactive Answer: c
Standard 18-carat gold contains: a) 82 parts gold, 18 parts metal b) 18 parts gold, 82 parts metal c) 18 parts gold, 6 parts other metal d) 9 parts gold, 15 parts other metal Answer: c
Phosphorus is kept under water because: a) Its ignition temperature is high b) Its ignition temperature is low c) Its critical temperature is high d) Its critical temperature is low Answer: b
