A 0.191g piece of solid aluminum reacts with gaseous oxygen from the atmosphere to form solid aluminum oxide. In the laboratory, a student weighs the mass of the aluminum oxide collected from this reaction as 0.199 g. The 0.191g solid aluminum is the .A) percent yield,
B) excess reagent,
C) limiting reagent,
D) actual yield,
E) theoretical yield

Answer : The correct option is, (C) limiting reagent

Explanation :

Excess reagent : It is defined as the reactants not completely used up in the reaction.

Limiting reagent : It is defined as the reactants completely used up in the reaction.

Theoretical yield : It is calculated from the amount of the limiting reagent present in the reaction.

Actual yield : It is experimentally determined.

Percent yield : It is the percent ratio of actual yield to the theoretical yield.

The balanced chemical reaction will be:

In this reaction, aluminium is a limiting reagent that limits the formation of product and the oxygen is an excess reagent.

Hence, the 0.191 g solid aluminum is the limiting reagent.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

it is the most commonly accepted one