Please, could you help me with this chemistry question?.

when heated, potassium chlorate decomposes into potassium chloride and oxygen.
#2KClO_3 to 2KCl+O_3#
what will be the theoretical yield of potassium chloride if 10g of potassium chlorate was used?

1 Answer
Feb 18, 2018

#5.96 \ "g"~~6 \ "g"#

Explanation:

Well, we first need to write down the balanced equation for this:

#2KClO_3(s)->2KCl(s)+3O_2(g)#

As you can see here, the mole ratio between potassium chlorate #(KClO_3)# and potassium chloride #(KCl)# is #2:2=1#.

Since we have used #10 \ "g"# of potassium chlorate, we need to convert that amount into moles.

We know that potassium chlorate has a molar mass of

#122.55 \ "g/mol"#

So, we have used

#(10 \ cancel"g")/(122.55 \ cancel"g""/mol")~~0.08 \ "mol"#

So, we are also going to produce #0.08 \ "mol"# of potassium chloride.

#KCl# has a molar mass of #~~74.55 \ "g/mol"#.

So, the amount of potassium chloride that we are going to produce in grams will be

#74.55 \ "g""/"cancel"mol"*0.08cancel"mol"~~5.96 \ "g"#

Rounding off to the nearest whole number since the amount of reactants given is a whole number, that equates to #6 \ "g"# of #KCl# produced.