A mass of #2.40*g# of calcium oxide is obtained by heating a mass of #5.00*g# calcium carbonate. What is the stoichiometric equation that represents the formation of calcium oxide, and what is the percentage yield?

1 Answer
Mar 12, 2017

Answer:

We need a stoichiometrically balanced equation to represent the decomposition of calcium carbonate..........

Explanation:

#CaCO_3(s) + Delta rarr CaO(s) + CO_2(g)uarr#

The #Delta# symbol represents heat, and you have to fiercely heat these carbonates to effect decomposition. Note that this reaction is certainly stoichiometrically balanced: garbage in equals garbage out.

#"Moles of calcium carbonate "=" "(5.00*g)/(100.09*g*mol^-1)#

#=# #0.0500*mol#

#"Moles of calcium oxide "=" "(2.40*g)/(56.08*g*mol^-1)#

#=# #0.0428*mol#

#"% yield"# #=# #(0.0428*mol)/(0.0500*mol)xx100%=86%#

Are you happy with this?

Note that most carbonates behave this way under heat:

#MCO_3(s) + Delta rarr MO(s) + CO_2(g)uarr#