Chemistry
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
Related Questions
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
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.
A reaction of a type: AB + CD ⟶ AD + CB, involves
(i) no chemical change
(ii) decomposition of AB and CD
(iii) exchange of ions of AB and CD
(iv) combination of AB and CD
The reaction:
BaCl2 (aq) + H2SO4 (aq) ⟶ BaSO4 (s) + 2HCl (aq) is
(i) displacement reaction
(ii) neutralisation reaction
(iii) decomposition reaction
(iv) double displacement reaction