Find the number of moles of water that can be formed if you have 138 mol of hydrogen gas and 64 mol of oxygen gas.

Answer : The number of moles of water formed can be, 128 moles

Solution : Given,

Moles of hydrogen gas = 138 moles

Moles of oxygen gas = 64 moles

First we have to calculate the limiting and excess reagent.

The balanced chemical reaction will be,

From the balanced reaction we conclude that,

As, 2 moles of hydrogen gas react with 1 mole of oxygen  gas

So, 138 moles of hydrogen gas react with moles of oxygen  gas

But the given moles of oxygen gas is 64 moles.

That means oxygen gas is a limiting reagent and hydrogen gas is an excess reagent.

Now we have to calculate the moles of water.

From the reaction we conclude that,

As, 2 moles of oxygen react to give 1 mole of water

So, 64 moles of oxygen react to give moles of water

Therefore, the number of moles of water formed can be, 128 moles