# AS level chemistry questionWatch

#1
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.

0
8 months ago
#2
find number of moles of hydrogen
from equation deduce number of moles of ethane
hence find theoretical mass of ethane
hence from % yield, find actual mass of ethane
(Original post by sahil kumar)
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.

0
#3
(Original post by BobbJo)
find number of moles of hydrogen
from equation deduce number of moles of ethane
hence find theoretical mass of ethane
hence from % yield, find actual mass of ethane
Hi i did all of those steps still turned out to be wrong

number of moles of hydrogen = 8.1
number of moles of ethane =4.05
theoretical mass = 121.5
%yield = should be 78. 98 but im getting 7654.5 for sone reason lmao
0
8 months ago
#4
(Original post by sahil kumar)
Hi i did all of those steps still turned out to be wrong

number of moles of hydrogen = 8.1
number of moles of ethane =4.05
theoretical mass = 121.5
%yield = should be 78. 98 but im getting 7654.5 for sone reason lmao
not sure what you are putting in the calculator to get that

Actual Mass / Theoretical mass = Percentage yield

so Actual mass = Percentage yield x Theoretical mass = 65/100 x 121.5 which does give 78.98g
0
#5
(Original post by BobbJo)
not sure what you are putting in the calculator to get that

Actual Mass / Theoretical mass = Percentage yield

so Actual mass = Percentage yield x Theoretical mass = 65/100 x 121.5 which does give 78.98g
Thanks man got it i forgot to divide the 65/100
0
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