Question

On dissolution in water, which of the following is highly exothermic?

• A. Graphite, $C\left(s\right)$
• B. Sodium hydroxide, $NaOH\left(s\right)$
• C. Iodine, $I_2\left(s\right)$
• D. Sucrose, $C_{12}{H}_{22}{O}_{11}\left(s\right)$
• E. Iron(III) chloride, $FeC{l}_3\left(s\right)$

Answer 1

The correct option is B Sodium hydroxide, $NaOH\left(s\right)$

On dissolution in water, sodium hydroxide, NaOH(s) is highly exothermic.
Thus, when you add few pelletes of NaOH to a beaker containing water and stirr the solution, you will observe that beaker is warmed up.