Question

Which of the following metals will react with water to produce a metal hydroxide and hydrogen gas? (2 points)
K
Sn
Ni
Mn

Answer 1

The answer would be the first option - k

Answer 2

Answer: The correct answer is Potassium (K).

Explanation:

Alkali (Group 1) and Alkaline earth (Group 2) elements react with water to produce metal hydroxide and also releases hydrogen gas.

Reaction of group 1 elements with water:

$2M+2H_2O\rightarrow 2MOH+H_2$

Reaction of group 2 elements with water:

$M+2H_2O\rightarrow M(OH)_2+H_2$

From the given options:

Potassium (K): This metal belongs to Group 1 and readily reacts with water to form potassium hydroxide and hydrogen gas.

$2K+2H_2O\rightarrow 2KOH+H_2$

Tin (Sn): This element belongs to Group 14 and does not readily reacts with water.

Nickel (Ni): This element belongs to Group 10 and does not readily reacts with water.

Manganese (Mn): This element belongs to Group 7 and does not readily reacts with water.

Hence, the correct answer is potassium (K).