A chemistry has 14.5 g of Al and 7.5 g of #O_2#. What would the excess be for the following reaction: #4Al + 3O_2 -> 2Al_2O_3#?
Al is in limiting
To check excess and limiting reactants, the number of moles has to be found, and then divided by the coefficient.
For the sake of shortening the equations, let us say that:
To find the number of moles, we need to use the formula:
The mass is given in the question:
Molar mass of Al and Oxygen can be found in periodic table,
(since oxygen gas (
Now putting these values for the number of moles's formula:
After getting the number of moles, we just still have to divide them by their respective coefficients, and comparing them.
The reactant with the bigger value will be in excess and the reactant with the smaller value will be in limiting
Therefore, Al is in limiting (there is less of it and thus it is limiting the reaction) and
Hope that this will help. :)