Advertisements
Advertisements
प्रश्न
Give a reason why
Freezing of water is a reversible change while burning of a candle – an irreversible change.
उत्तर
Freezing of water is reversible change as on heating frozen ice changes to water by heating.
Burning of a candle is irreversible change as on reversing the conditions we can not get candle back out of CO2, water vapours and wax vapours.
APPEARS IN
संबंधित प्रश्न
Classify the following as chemical or physical change:
Passing of electric current through water, and water breaking down into hydrogen and oxygen gases.
Try segregating the things around you as pure substances or mixtures.
State the differences between a physical change and a chemical change.
State whether the following is physical or chemical changes.
(energy produced) dissolving sugar in water —
Tick (√) the correct alternative from the choice given for the following statement.
The compound rust is a hydrated oxide of
Make a list of different types of changes with example.
State which of the following pertain to – chemical changes.
(a) Substance retains its identity
(b) The change is permanent
(c) No new substance is formed
(d) Is easily reversible
(e) Produces one or more new substances by a change in its composition
(f) The change is temporary
(g) The composition and properties of the original substance are not altered.
Give a reason why – Addition of zinc nitrate to water is a physical change but, the addition of zinc to dilute nitric acid is a chemical change.
______ is the substance that is dissolved in a solvent.
Cutting a log of wood into pieces is a chemical change.
