Chemistry
Write the chemical reaction where the following changes are observed.
(a) Gas is evolved
(b) Colour change is noticed
(c) Precipitate is formed
(d) Physical state of reactants is changed
Related Questions
Define :
(a) Photochemical reaction
(b) Electrochemical reaction.
Give one example in each case.
Give an example of each of the following chemical changes.
(a) A photochemical reaction involving 1. silver salt 2. water
(b) A reaction involving 1. blue solution 2. formation of a dirty green precipitate
(c) Two gases combine to form a white solid.
(d) Two solids combine to form a liquid.
(e) A reaction where color change is noticed.
Give a reason for the following :
(a) Silver nitrate solution is kept in coloured bottles.
(b) Molybdenum is used in the manufacture of ammonia.
(c) A blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
(d) Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Which of the following is not a characteristic of a chemical change?
(i) It is irreversible
(ii) No net energy change is involved
(iii) New substance is formed
(iv) Involves absorption or liberation of energy