Question

Identify limiting and excess reagents when 25g of nitrogen reacts with 25g of hydrogen. How many grams of ammonia gas are formed in this reaction?

Answer 1

Answer:

Nitrogen is limiting reactant while hydrogen is in excess.

Explanation:

Given data:

Mass of N₂ = 25 g

Mass of H₂ = 25 g

Mass of ammonia formed = ?

Solution:

Chemical equation:

N₂ + 3H₂    →     2NH₃

Number of moles of Nitrogen:

Number of moles = mass/ molar mass

Number of moles = 25 g/ 28 g/mol

Number of moles = 0.89 mol

Number of moles of hydrogen:

Number of moles = mass/ molar mass

Number of moles = 25 g/ 2 g/mol

Number of moles = 12.5 mol        

Now we will compare the moles of both reactant with ammonia.

                   H₂            ;             NH₃

                    3             :              2

                    12.5        :            2/3×12.5 = 8.3

                 

                   N₂            ;             NH₃

                    1              :              2

                    0.89        :            2×0.89 = 1.78

The number of moles of ammonia produced by nitrogen are less thus nitrogen is limiting reactant while hydrogen is in excess.