Question

7 C₉H₈O₄ + 9 CH₃OH = 9 C₈H₈O₃ + 10 H₂O

I need to find the limiting reactant and the the theoretical yield for the above reaction. I am stuck. I used 1 tablet of aspirin, 4 mL total of methanol, and 0.5 g of aluminum. I just do not know where to start....ugh organic chemistry

Answer 1

No problem at all,this is a physical chemistry problem though

you need to find :

density of methanol , so that you can find its mass

4 mL x density = mass of methanol

1 tablet mass you have to see it yourself

limiting reactant is the one which gives the least amount of product

from reaction we see that:

7 mol C9H8O4 forms 9 mol C8H8O3

1 mol mass 180.157 g 1 mol mass 152.15 g

7 mol = 1263.99g 9 mol = 1369.35g

1 g aspirin 1369.35g/1263.99g = 1.083355g

similarly for methanol CH₄

9 mol methanol = 288.36 g   forms 9 mol C8H8O3 = 1369.35g

1g methanol forms 1369.35g/ 288.36g = 4.7487g

so density of methanol = 792 kg/m³ = 0.792g/mL

mass of 4 mL methanol = 3.168g

1g methanol forms = 4.7487g

3.168g forms = 15.04388g  C8H8O3

while if the tablet is 500mg as it is not mentioned in you question

1 g aspirin 1369.35g/1263.99g = 1.083355g C8H8O3

500mg = 0.5g forms = 1.083355 g x 0.5 = 0.54168 g C8H8O3

here 1 tablet aspirin forms less amount of product and hence it is limiting reactant

theoretical yield is based on limiting reactant

mass of   C8H8O3 produced = 0.54168 g = theoretical yield