Answer:Limiting reagent is
B) O₂
Explanation:
From the balanced reaction.
C3H8 + 5O2 ==> 3CO2 + 4H2O
there are two reagents(C3H8 and O2)and the limiting one is the one that is used up before the end of the reaction .
C3H8 : 02 = 1:5
Given mass 50g of propane
Molar mass = (3×12 + 8×1) =44g/mol
Mole= 50/44 = 1.136mol.
Given 120g of oxygen gas
Molar mass =32g/mol
Mole = 120/32= 3.75mol.
From the ratio, for the complete reaction, oxygen needs 5× of propane = 5×1.136= 5.68mol , but it has less (3.75mol)
Therefore O₂ is the limiting reagent.