If 4.34 moles of potassium react with excess water, how many moles of hydrogen gas would be produced at STP

2.17 mol

Explanation:

Given data:

Number of moles of potassium = 4.34 mol

Moles of hydrogen gas produced at STP = ?

Solution:

Chemical equation:

2K + 2H₂O  →  2KOH + H₂

Now we will compare the moles of hydrogen and potassium.

                           K            :           H₂

                            2           :            1

                            4.34      :          1/2×4.34 = 2.17 mol

So, from 4.34 moles of potassium 2.17 moles of hydrogen are produced at STP.