The question is incomplete, here is the complete question:
Methanol, is made by using a catalyst to react carbon monoxide with hydrogen at high temperature and pressure. Assuming that 450.0 mL of CO and 825 mL of [tex]H_2[/tex] are allowed to react, answer the following questions. (Hint: First write the balanced chemical equation for this reaction.)
Which reactant is in excess?
Answer: The excess reactant in the reaction is carbon monoxide.
Explanation:
Excess reactant is defined as the reactant which is present in large amount in a reaction. The formation of product does not depend on this reactant and some amount of it remains after the completion of the reaction.
We are given:
Mass of CO = 450.0 mL
Mass of hydrogen gas = 825 mL
The balanced chemical equation for the reaction of carbon monoxide and hydrogen gas follows:
[tex]CO+2H_2\rightarrow CH_3OH[/tex]
By Stoichiometry of the reaction:
2 mL of hydrogen gas reacts with 1 mL of carbon monoxide
So, 825 mL of hydrogen gas will react with = [tex]\frac{1}{2}\times 825=412.5mL[/tex] of carbon monoxide
As, given amount of carbon monoxide is more than the required amount. So, it is considered as an excess reagent.
Hydrogen gas is considered as a limiting reagent because it limits the formation of product.
Hence, the excess reactant in the reaction is carbon monoxide.
