Question

What will happen when a burning matchstick is taken close to the mouth of the test tube containing magnesium metal and sodium hydroxide?​

Answer 1

Explanation:

When a matchstick is brought near the mouth of the test tube in which a metal has reacted with sulphuric acid, the matchstick produces a pop-sound nd stops burning. this is due to evolution of hydrogen gas after the reaction.

METAL + ACID ---------> SALT + HYDROGEN GAS

eg. Zn + H2SO4 ----------> ZnSO4 + H2

THE POP SOIND MADE IS DUE TO THE EVOLUTION OF HYDROGEN GAS, THEREBY, BURNING OUT THE FLAME.

HOPE IT HELPS!