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

Question

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

Jeremiah Adams · Accepted Answer

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

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?

Naomi Aronson · Answer

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

I believe you've already overcome the difficult part because you have the chemical reaction balanced. Now that we have the chemical reaction, we can use it. By reading the coefficients, we can obtain the stoichiometric ratios.

As an illustration...

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.

You did not specify how much water reacts, so we assume that there is excess water.... and so on.

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).

Natalie Anton · Answer

undefined 2 moles of C2H2 will be produced.