The Student Room Group

percentage yield questions

1. Phenol, C6H5OH, is converted into trichlorophenol, C6H2Cl3OH. If 488 g of product are obtained from 250 g of phenol, calculate the percentage yield.

2. 29.5 g of ethanoic acid, CH3COOH, are obtained from the oxidation of 25.0 g of ethanol, C2H5OH. What percentage yield does this represent?

3. 100 cm3 of barium chloride solution of concentration 0.0500 mol dm-3 were treated with an excess of sulphate ions in solution. The precipitate of barium sulphate formed was dried and weighed. A mass of 1.1558 g was recorded. Calculate the percentage yield.

Thanks

Reply 1

Welcome to TSR :smile:

Calculate the moles at the start for the reagent and the moles for the product at the end, then divide the two and multiply by 100.

Reply 2

it's experimental yield (what the experiment gave you) divided by theoretical yield (what you calculated) x 100. :smile:

Reply 3

So for the first question is 92.9% correct??

Reply 4

Yep :smile:

Reply 5

Yep :smile:


Would question 2 be 90.5%?

Reply 6

Would question 3 be 0.554%?

Reply 7

Original post by Ann_Onymous
Would question 2 be 90.5%?


8 years. How on Earth did you find this?

Reply 8

8 years. How on Earth did you find this?


I was trying to find some percentage yield questions online and this came up as one of the options. I knew it was old but I thought someone might answer it if I ask. 😅

Reply 9

for the first i got 51.4% did anyone else?