This is a limiting reagent problem. How do I know that? Because amounts of BOTH reactants are given. I solve these problems by solving two stoichiometry problems. First I use 1000g ethylene and all of the steam needed and calculate moles ethanol produced. Then I use 14 g steam and all of the ethylene needed and calculate the moles ethanol produced. There is a different answer produced and both answers can't be correct; however, in limiting reagent problems the smaller value is ALWAYS the correct one and the reagent producing that value is the limiting reagent. Here is a worked example of a stoichiometry problem. Just follow the steps. Post your work if you get stuck.
http://www.jiskha.com/science/chemistry/stoichiometry.html
Ethanol (C2H5OH) is synthesized for industrial use by the following reaction, carried out at very high pressure.
C2H4(g) + H2O(g) C2H5OH(l)
What is the maximum amount of ethanol (in grams) that can be produced when 1.0 kg of ethylene (C2H4) and 0.014 kg of steam are placed into the reaction vessel?
1 answer