Question
Give reasons:
A mixture of dilute NaOH and aluminium pieces is used to open drain.
Solution
Aluminium pieces dissolve in dilute NaOH to evolve dihydrogen gas whose presence can be used to open clogged drain.
2Al (s) + 2NaOH(aq) + 6H2O(l)
↓
2 Na+[Al(OH)4] –(aq) + 3H2(g)
Sodium
tetra hydroxo aluminate(III)
