A) write an equation to show the reaction of potassium metal with a) water b) sulphur?

Question

b) explain why these reaction should not be conducted in the laboratory without taking special precautions

Answer 1

a) 2K(s) + 2H2O(l) → H2(g) + 2KOH(aq)

potassium reacts violently with water, producing hydrogen. The reaction is notably more violent than that of lithium or sodium with water, and is sufficiently exothermic that the evolved hydrogen gas ignites.

b) K2S arises from the reaction of potassium and sulfur. In the laboratory, this synthesis is usually conducted in a solution of anhydrous ammonia.

Danger! Reacts violently with water liberating highly flammable gases. Causes eye and skin burns. Causes digestive and respiratory tract burns. May ignite or explode on contact with moist air. May form unstable peroxides.

http://www.unitednuclear.com/kmsds.htm