- 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