If 10 mol of #CaC_2# reacts with #H_2O#, how many moles of #C_2H_2# will be produced?

#CaC_2 + 2H_2O -> Ca(OH)_2 + C_2H_2#

2 Answers
Jun 1, 2017

Answer:

This is an acid base reaction.............

Explanation:

With water......

#Ca^(2+){C-=C}^(2-)+2H_2Orarr Ca(OH)_2+HC-=CH(g)uarr#

And the stoichiometry clearly indicates that ONE mole of calcium carbide, a mass of #64.1*g# reacts with TWO moles of water, #36*g# to give #74.1*g# calcium hydroxide, and #26*g# acetylene.

Is mass conserved in this reaction? Should it be?

And if you decompose #10* mol# calcium carbide you clearly gets #10* mol# acetylene. Agreed?

Jun 1, 2017

#"10 mols"# of #"C"_2"H"_2#.


Since you already have the chemical reaction balanced, I think you're past the hard part. Now we can use the chemical reaction. Reading off the coefficients, we have the stoichiometric ratios at our disposal.

For example...

  • For every one mol of #"CaC"_2#, one mol of #"Ca"("OH")_2# is produced.

  • For every one mol of #"CaC"_2#, one mol of #"C"_2"H"_2# is produced.

  • For every one mol of #"CaC"_2#, two mols of water react.

... and so on. You didn't say how much water reacts, so we assume excess water.

From the second bullet point, we know that #"CaC"_2# and #"C"_2"H"_2# have a #1:1# mol ratio. For emphasis, this is saying:

#color(red)(1)CaC_2 + 2H_2O -> Ca(OH)_2 + color(red)(1)C_2H_2#

So, you apparently already have the number written down. It is #color(blue)("10 mols")# of #"C"_2"H"_2# that is produced (assuming the water is in excess).