The making of a ring from gold is a ______ change and making a statue from wood is a _______ change
Irreversible, reversible
Reversible, irreversible
Irreversible, irreversible
Reversible, reversible
The following reaction is a
Mercuric oxide = Mercury + oxygen
Chemical combination reaction
Chemical displacement reaction
Chemical decomposition reaction
Physical change
Which of the following is a feature of physical change ?
It is reversible
It is temporary
No new substance is formed
All of these
On decreasing temperature, a liquid turns into solid. This is
Condensation
Melting
Freezing
Sublimation
When liquids are heated, they turn into gases. The yellow egg yolk present inside the egg is a liquidbut 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
A chemical reaction in which energy is liberated is called
Exothermic reaction
Endothermic reaction
Photo chemical reaction
When two substances interact in a change:
The rate and extent of change is always the same
The rate and extent of change depend on the conditions under which the change occurs
Only the rate depends on the conditions under which the change occurs, and the extent remains same
The extent of change may vary, but the rate of change is always the same
Chemical changes initiated by light are called
Photochemical changes
Spectroscopic changes
Periodic changes
Electrochemical changes
To cook a particular dish, the optimum temperature is 700 c. At 500 c the dish will
Get cooked slower
Get cooked faster
Not get cooked at all
Study of photo-chemical reaction is called:
Photonics
Photography
Photochemistry
