In which type of change a new substance is formed?
  • In physical change
  • In chemical change
  • In both (a) and (b)
  • In neither of these
Which among the following is a physical change?
  • Cutting a log of wood in small pieces
  • Burning of wood
  • Ripening of fruit
  • Cooking of food
Which is a method to prevent rust?
  • Crystallization
  • Sedimentation
  • Galvanisation
  • None of these
How crystal of pure substances are obtained?
  • By crystallization
  • By chromatography
  • By peptization
  • By all these methods
What will happen if carbon dioxide gas is passed through lime water ?
  • Calcium carbonate is formed
  • The lime water turns milky
  • Both of these
  • None of these
Iron pillar near the Qutub Minar in Delhi is famous for the following facts. Which of these facts is responsible for its long stability?
  • It is more than 7 metres high
  • It weighs about 6000 kg
  • It was built more than 1600 years ago
  • It has not rusted after such a long period
Galvanisation is a process used to prevent the rusting of which of the following?
  • Iron
  • Zinc
  • Aluminium
  • Copper
Paheli’s mother made a concentrated sugar syrup by dissolving sugar in hot water. On cooling, crystals of sugar got separated. This indicates a:
  • physical change that can be reversed
  • chemical change that can be reversed
  • physical change that cannot be reversed
  • chemical change that cannot be reversed

Meaning of the word "anhydrous" is

  • with water
  • without water
  • with copper
  • without copper

The color of solid magnesium is

  • dark grey
  • silver grey
  • black
  • whitish silver

Ammonia is

  • green in color
  • blue in color
  • colorless
  • brown in color

When liquids are heated, they

  • expand more than gases but less than solids
  • expand more than solids but less than gases
  • do not expand
  • none of above

Gases are compressible because of

  • space between particles
  • collision of particles
  • movement of particles
  • attraction force between particles

Number of gases joined together to make PVC is

  • 2
  • 3
  • 4
  • 5

The formula of ammonia is

  • NH2
  • NH3
  • NH4
  • NH5

The definite 'volume'

  • has solids only
  • has liquids only
  • has gases only
  • has solids and liquids both

The mixture of iron and sulphur is separated by

  • filtration
  • magnet
  • distillation
  • evaporation

What are the chemicals used in fireworks?

  • copper chloride
  • calcium chloride
  • barium chloride
  • all of above

As compare to gases, liquids are

  • incompressible
  • compressible
  • more compressible than liquids
  • less compressible than liquids

Bakelite is a good

  • conductor
  • insulator
  • metal
  • solid

When gases are heated, they

  • expand more than solids but less than liquids
  • expand more than liquids but less than solids
  • do not expand
  • both b and c

The particles of iron sulfide are

  • physically bonded
  • chemically bonded
  • biologically bonded
  • permanently bonded

Plastic was accidently invented when the inventor was trying to make

  • a cup for coffee
  • an artificial ivory of billiard balls
  • an artificial sword for martial arts training
  • his favourite dish

The density of 'solids' is

  • lower than liquids but higher than gases
  • higher than liquids but lower than gases
  • higher than both liquids and gases
  • lower than both liquids and gases

When methane is combusted, it combines with

  • carbon dioxide
  • oxygen
  • hydrogen
  • nitrogen

The new form of 'polythene' is called

  • polypropene
  • polybutene
  • high density polyethene
  • low density polyethene

The shape of 'gas' is

  • indefinite
  • definite
  • indescribable
  • dependent on air humidity

One of the main components of fertilizers is

  • ammonia
  • chlorine
  • hydrogen
  • methane

Other than carbon and hydrogen, finished plastic may contain

  • nitrogen and phosphorus
  • nitrogen and oxygen
  • sulphur and iron
  • magnesium and nitrogen

The short form of "Polyvinyl chloride" is

  • PVCl
  • PViCl
  • PVC
  • PoViCl
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