BioMedical Admissions Test (BMAT) 2025 – 400 Free Practice Questions to Pass the Exam

Alkali metals, which include lithium, sodium, potassium, rubidium, cesium, and francium, are well-known for their highly reactive nature, particularly with water. When alkali metals react with water, they undergo a vigorous reaction. The primary characteristic of this reaction is the formation of a metal hydroxide along with the release of hydrogen gas.

During the reaction, the alkali metal displaces hydrogen from water, leading to the formation of a solution of metal hydroxide and hydrogen gas as a byproduct. For example, when sodium reacts with water, sodium hydroxide is formed, and hydrogen gas is released:

\[ 2 \text{Na} + 2 \text{H}_2\text{O} \rightarrow 2 \text{NaOH} + \text{H}_2 \uparrow \]

The formation of metal hydroxides is significant because these compounds are alkaline (basic) when dissolved in water, which contributes to the strong basicity seen in alkali metal hydroxides.

The other choices do not accurately represent the typical reactions of alkali metals with water:

- The first option mentioning the formation of oxides is misleading, as oxidation does occur but does not primarily describe the interaction with water.