Q1. What is formed in the reaction of sodium hydroxide with zinc?
A Zinc hydroxide and hydrogen gas
B Zinc hydroxide and sodium
C Sodium zincate and hydrogen gas Correct
D Sodium zincate and water
Explanation
Zinc is an amphoteric metal, so it reacts with a strong base such as sodium hydroxide to form sodium zincate and hydrogen gas. The reaction shows zinc dissolving in alkali while hydrogen is released. Zinc hydroxide with hydrogen gas is not the final product named in this alkaline reaction. Zinc hydroxide with sodium is chemically unsuitable because sodium metal is not liberated. Sodium zincate with water misses the characteristic evolution of hydrogen gas, which is the key product alongside sodium zincate.