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प्रश्न
Give one example electrochemical reaction.
Give an example electrochemical reaction.
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उत्तर
Acidulated water breaks into hydrogen and oxygen.
\[\ce{2H2O ->[Electricity] 2H2 + O2}\]
संबंधित प्रश्न
Fill in the blank.
The formation of gas bubbles in a liquid during a reaction is called ......................
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
FILL IN THE BLANK
........... electrolytes dissociate completely in aqueous state and allow large amount of electricity to flow through it.
FILL IN THE BLANK
Distillation is a method of obtaining pure ............. from a solution.
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Thermal decomposition of mercury [II] oxide.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Zinc carbonate.
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
Classify each of the following, as a physical or a chemical change. Give reasons.
(a) Drying of a shirt in the sun.
(b) Rising of hot air over a radiator.
(c) Burning of kerosene in a lantern.
(d) Change the colour of black tea by adding lemon juice to it.
(e) Churning of milk cream to get butter.
______ is the chemical name of rust.
Write the effects of chemical reactions.
