Q. Which of the following metals do/does not react with cold water?

1. Potassium
2. Sodium
3. Magnesium
4. Aluminium

Select the correct answer from the codes given below:
Answer: Only 3 and 4
Notes: Metals react with water and produce a metal oxide and hydrogen gas. Metal oxides that are soluble in water dissolve in it to further form metal hydroxide. Metals like potassium and sodium react violently with cold water. In case of sodium and potassium, the reaction is so violent and exothermic that the evolved hydrogen immediately catches fire. Magnesium does not react with cold water. It reacts with hot water to form magnesium hydroxide and hydrogen. Metals like aluminium, iron and zinc do not react either with cold or hot water. But, they react with steam to form the metal oxide and hydrogen.

This question is part of UPSC Daily 20 MCQ Series Course on GKToday Android app.