In an endothermic reaction:
Energy is released
Energy is absorbed
Energy is neither released nor absorbed
Energy is not required
On decreasing temperature, a liquid turns into solid. This is:
Condensation
Melting
Freezing
Sublimation
Which of the following is a feature of physical change?
It is reversible
It is temporary
No new substance is formed
All of these
We keep food at low temperature in a refrigerator because it:
Saves money
Makes food more tastier
Kills bacteria present in the food
In fashionable to keep the food in the refrigerator
Dissolving salt in water is a/an:
Endothermic change
Exothermic change
Both A and B
Chemical combination
The growth of seedlings in a crop is a:
Undesirable change
Desirable change
Reversible change
Physical change
When nitrogen reacts with hydrogen under high temperature and pressure ammonia, which is also a gas is formed. This is an example of:
Chemical decomposition
Oxidation
When liquids are heated, they turn into gases. The yellow egg yolk present inside the egg is a liquid but when it is heated, it changes into an omelet which is solid, why?
Sometimes, liquids turn into solids
Omelet does not follow the above rule
Strictly speaking, the rule does not apply to complex mixtures and egg yolk is a complex mixture
None
When a solid directly turns into gaseous state, it is called:
Polymerisation
Melting of ice is an example of:
Exothermic reaction
Endothermic reaction
