Question

diethyl ether is produced from ethanol according to the following equation 2CH3CH2OH--->CH3CH2OCH2CH3+H2O What mass of ether will be produced if 221 g of ethanol reacts with a 66.5 percent yield??

Answer 1

find the theoretical yield and multiply it by the percent yield (0.665).

Answer 2

if you need finding the theoretical yield, convert the mass given of reactant to moles and follow this:

Use the stoichiometric coefficients to find moles produced.
Set up a ratio using the species of interest, like so:

e.g. for a general reaction:

\(\color{red}{a}A + \color{blue}{b}B\) \(\rightleftharpoons\) \( \color{green}{c}C\)

where upper case are the species (A,B,C), and lower case (a,b,c) are the coefficients ,

\(\dfrac{n_A}{\color{red}{a}}=\dfrac{n_B}{\color{blue}{b}}=\dfrac{n_C}{\color{green}{c}}\)

From here you can isolate what you need.
For example: if you have 2 moles of B, how many moles of C can you produce?

solve algebraically: \(\dfrac{2}{\color{blue}{b}}=\dfrac{n_C}{\color{green}{c}}\rightarrow n_C=\dfrac{2*\color{green}{c}}{\color{blue}{b}}\)
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To convert mass to moles, use the relationship:

\(n=\dfrac{m}{M}\)

where, M=molar mass, m=mass, and n= moles.