Answer:
The limiting reactant = hydrogen
The theoretical yield = 1404 grams
Explanation:
1- getting the limiting reagent:
The reaction between hydrogen and oxygen to form water can be expressed using the following equation:
2 H₂ + O₂ ...........> 2 H₂O
From the balanced equation, we can note that:
2 moles of hydrogen are required to react with 1 mole of oxygen. This means that the ratio is 2:1 which means that for a certain number of oxygen moles, twice that number of hydrogen moles is required.
This means that:
For 78 moles of oxygen , 78*2 = 156 moles of hydrogen are required.
Since only 78 moles of hydrogen are present, therefore, hydrogen is our limiting reagent.
This means that the reaction would stop once the amount of hydrogen is consumed. This also means that we would base all our further calculations on the amount of hydrogen present.
2- getting the theoretical yield:
Again, the balanced equation is:
2 H₂ + O₂ ...........> 2 H₂O
From this equation, we can note that:
2 moles of hydrogen produce 2 moles of water.
This means that 78 moles of hydrogen would also produce 78 moles of water.
The theoretical yield will be equivalent to the mass of 78 moles of water.
mass of water = number of moles * molar mass
mass of water = 78 * 18
mass of water = 1404 grams
Hope this helps :)
