Question

Flowers of sulphur boiled with calcium hydroxide chemical reaction

Answer 1

Flowers of sulfur is a form of bright yellow powder of sulfur that is obtained from naturally occurring volcanic brimstone deposits. Sulfur is a chemical element  that has the symbol S.

Calcium hydroxide, Ca(OH)₂, is an inorganic compound that is formed from the reaction of calcium oxide (CaO) and water (H₂O). 

The reaction between calcium hydroxide and sulfur forms what is known as lime sulfur. Lime sulfur can be obtained by boiling calcium hydroxide, also known as quick lime, and sulfur in the presence of surfactant. This reaction forms a mixture of what are  known as calcium polysulfides (CaSx).

The direct reaction equation for calcium hydroxide and sulfur requires small amounts of surfactant. 

Ca(OH)₂ + H₂S = CaS + 2 H₂O

Note: This is the possible reaction of creating lime sulfur from Ca(OH)2. This means that the sulfur must first react to from H₂S, to be used to form the calcium Sulfide.

Calcium sulfide ( CaS) can also be formed by the carbothermic reduction of calcium sulphate: 

CaSO₄ + 2 C → CaS + 2 CO₂