Alkali metals react with water vigorously to form hydroxides and dihydrogen. Which of the following alkali metals reacts with water least vigorously?
Alkali metals react with water and form hydroxides and dihydrogen.
2M + 2H2O → 2M+ + 2OH- + H2 where M is an alkali metal. Lithium has the most negative EӨ value, however it has the least vigorous reaction with water. It is even less vigorous than sodium, which has the least negative EӨ value. This is because of the small size of Li and its high hydration energy. It is also because Li has the highest melting point. The correct answer is (i).