Question

How does `"calcium carbide"` react with `"water"`?

Answer 1

Well it is simply an acid base reaction.

Explanation:

`Ca^(2+){C-=C}^(2-) + 2H_2O(l) rarr HC-=CH(g)uarr +2Ca(OH)_2(aq)`

This reaction used to be the basis of the old miners' lamp. A miner would take a lump of the carbide, moisten it with a bit of water, stick it in a lantern on his helmet, and light the acetylene gas evolved to provide illumination.

`HC-=CH(g) + 5/2O_2(g) rarr 2CO_2(g) + H_2O(l)`

Of course, the naked flame constituted a very significant safety hazard underground, in that combustible gas in the mine or the cave would ignite. Later versions enclosed the flame in gauze.