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

1 Answer
Oct 31, 2016

Well it is simply an acid base reaction.


#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.