00:01
Hi, so we are to calculate the theoretical yield and then the percent yield of the reaction.
00:06
So we have here the balance equation is already given.
00:09
So let's identify first the limiting reactant in our reaction.
00:15
We'll do that by converting the given mass of the reactants to moles.
00:19
Number of moles of nh3, if we have 74 .2, this is kilograms, convert this to grams because we will be using the molar mass in terms of grams.
00:31
One kilogram is equivalent to 1000 grams.
00:34
The molar mass of nh3 is 74 .04 grams here and then moles in the numerator.
00:42
Now we cancel kilograms grams and we'll get 4354 .46.
00:50
This is moles of nh3 and then for co2, if we have 105 kilograms, convert to grams.
01:00
One kilogram is 1000 grams and then the molar mass of co2 is 44 .01 grams here and then moles in here.
01:11
Now we cancel kilograms, grams, grams and we'll get 2385 .82.
01:20
This is moles of co2.
01:23
Now we will solve for the mole ratio.
01:27
So mole ratio in this case is the number of moles of the reactant divided by the coefficient of that reactant from the balance equation.
01:35
So let's start with ammonia.
01:37
We have 4354 .46 divided by the coefficient of ammonia from the balance equation which is 2.
01:44
So we'll have 2177 .23.
01:50
For co2, we have 2385 .82 divided by 1.
01:55
So we'll have 2385 .82 also.
01:59
So whichever gives the smallest mole ratio will be the limiting reactant.
02:04
So that means ammonia is our limiting reactant here, our reactant.
02:10
So why did we have to identify the limiting reactant first? because the amount of the limiting reactant will be the basis on the amount of the products formed.
02:17
Now we could calculate for the theoretical yield which is the mass of urea.
02:24
That's ch4n2o...