Question

A tube containing 3 mL if 6 M HCl, add a piece of mossy zinc. What is the balanced equation and reaction type? Next, a gas evolves and a lighted splint is inserted to the tube. What is the balanced equation and reaction type? So, reaction one is before splint and reaction 2 is after splint. Please explain and show steps.

Answer 1

Since the reduction potential of H⁺ is more, Zn reduces H⁺ to H2 gas and itself get oxidised to ZnCl2. Hence the baalnced chemical reaction is

Zn(s) + 2HCl(aq) ----------------> ZnCl2(s) + H2(g)

Since Zn displaces H⁺ ion from HCl, this is an example of single displacement reaction.

Here the gas evolved is H2 gas.

Since H2 gas is highly flammable, when a lighted splint is inserted to the tube, H2 gas will react with O2 gas in air to form H2O. This reaction gives a squeaky pop sound. The balanced chemical reaction is

2H2(g) + O2(g) ------------> 2H2O(l)