The reaction between solid white phosphorous and oxygen produces solid tetraphosphorous decaoxide (P4010). The balanced
equation is given below:
P4 +502 → P4010

What is the limiting reactant if you are using 25.0 grams of phosphorus and 50.0 grams of oxygen?

oxygen is limiting reactant

Explanation:

Given data:

Mass of phosphorus = 25.0 g

Mass of oxygen = 50.0 g

What is limiting reactant ?

Solution:

Chemical equation:

P₄   +  5O₂       →      P₄O₁₀

Number of moles of P₄:

Number of moles = mass/molar mass

Number of moles = 25.0 g/ 123.89 g/mol

Number of moles = 0.20 mol

Number of moles of  O₂:

Number of moles = mass/molar mass

Number of moles = 50.0 g/ 32 g/mol

Number of moles = 1.56 mol

now we will compare the moles of reactants with product:

        P₄          :            P₄O₁₀

         1           :              1

      0.20       :          0.20

      O₂           :         P₄O₁₀

       5            :         1

     1.56         :        1/5×1.56 = 0.312 mol

Less number of moles of product are formed by the oxygen thus it will act as limiting reactant.