Which of the following is NOT a chemical reaction?
a) rusting
b) frying an egg
c) melting of ice
When copper sulphate solution is mixed with sodium hydroxide solution, the chemical reaction is indicated by……..
a) emission of gas
b) odour change
c) temperature change
What happens when few drops of iodine solution is added in starch solution?
a) precipitates are formed
b) gas is emitted
c) colour change occurs
d) bad odour is emitted
Which of the following is not a balanced chemical reaction?
a) H2 + Cl2 ----à 2HCl
b) H2 + O2 ----à 2H2O
c) C + O2 ----à CO2
d) 2NH3ß----àN2 +3H2
