Question

Give one example of each : (a) chemical reaction showing evolution of gas. (b) change in substance's colour during a chemical reaction.

Answer 1

Answer:

1. zn + 2HCl to zncl2 +h2(gas)
2. zn + h2so4 to znso4(silver colour)+ h2

Explanation:

hope it helps

plz mark it as brainliest

try to follow me

Answer 2

Answer:

a) A common type of gas evolution reaction is an acid-base reaction, where an acid mixes with a base to produce water and carbon dioxide. ... For example, carbonic acid breaks down to water and carbon dioxide, sulfurous acid breaks down to water and sulfur dioxide, and ammonium hydroxide breaks down to water and ammonia gas.

b)Color changes from blue to light green. Copper reacts with oxygen, H2O and CO2 to give copper carbonate, which changes color from brown to blue or blue green. Rusting, blackening of surfaces of cut vegetables and fruits are other examples of change of color in a chemical reaction