The equation for the hydrogenation of ethyne is C2H2 + 2H2 --> C2H6.
The experimental yield is 65%.
What is the mass I'm grads of ethane that can be produced from 16.20g of hydrogen.
The answer is 79.98g, please explain thanks
Hard chemistry question AS Watch
- Thread Starter
- 09-06-2016 12:43
- 13-06-2016 11:54
Experimental yield =(theoretical number of moles)/(actual number of moles) * 100...equation 1
from the equation n(H2) : n(C2H6)
n(H2) = 16.2/2
n(C2H6) = 1/2 * n(H2
= 1/2 * 8.1
= 4.05 moles
let the theoretical number of moles be x
from equation one
Experimental yield = 65
actual number of moles of C2H6 = 4.05 moles
theoretical number of moles of C2H6= x moles
therefore 65 = x/4.05 *100
65/100 = x/4.05
0.65 * 4.05 = x
2.6325 moles = x
mass (C2H6) = Mr(C2H6) * n(C2H6)
= 30 * 2.6325
oops ours answers are slightly different but give it a check in the working
anywhere check this one out
Calculating Experimental Yields
1. Ensure you have a correctly balanced equation for the reaction performed.
2. Determine how many moles of each species were used in the reaction.
3. Determine which species is the limiting reagent, remembering to use the reaction stoichiometry.
4. From the weight of product obtained, determine how many moles of product this corresponds to.
5. Taking into account the stoichiometry, determine what % this is compared to what you could have obtained by 100 * [moles product obtained]/[ maximum moles product possible]
For example: 8.21g of cyclohexene was reacted with 17.5g of bromine in chloroform, giving 20g of trans-1,2-dibromocyclohexane.
Stoichiometry of this reaction is 1:1
Moles of each species involved:
cyclohexene = 0.10 mol, Br2= 0.11 mol, dibromocyclohexane = 0.083 mol.
Limiting reagent is therefore the cyclohexene.
Theoretical yield of dibromocyclohexane is 0.10 mol., therefore, experimental yield = 0.083./0.10 = 83 %