CBSE Class 10 Science 2020 · Paper 31/2/3 · Question 17(b)

Set-up (labelled diagram): a few pieces of magnesium ribbon are taken in a test tube held in a clamp on a stand, and dilute sulphuric acid is added. The mouth of the test tube is closed with a cork carrying a delivery tube, whose inner end is above the acid and whose outer end dips into soap solution in a trough. The gas formed passes through the delivery tube and fills soap bubbles; when a burning candle is brought near a gas-filled bubble, the gas burns with a pop sound, which shows that it is hydrogen. Labels: stand, clamp, test tube, magnesium ribbon, dilute sulphuric acid, cork, delivery tube, trough, soap solution, bubbles filled with hydrogen gas, burning candle. Equation: $\text{Mg}(s)+{\text{H}}_2{\text{SO}}_4(aq)⟶{\text{MgSO}}_4(aq)+{\text{H}}_2(g)\uparrow$