Be sure to answer all parts. Hydrogen gas has been suggested as a clean fuel because it produces only water vapor when it burns. If the reaction has a 81.2% yield, what mass of hydrogen forms 139 kg of water?

154.44 Kg of H₂

Explanation:

We'll begin by converting 139 Kg of water to grams. This can be obtained as follow:

1 kg = 1000 g

Therefore,

139 kg = 139 kg × 1000 g / 1 Kg

139 Kg = 139000 g

Next, the balanced equation. This is illustrated below:

2H₂ + O₂ —> 2H₂O

Next, we shall determine the mass of H₂ that reacted and the mass of H₂O produced from the balanced equation. This can be obtained as follow:

Molar mass of H₂ = 2 × 1 = 2 g/mol

Mass of H₂ from the balanced equation = 2 × 2 = 4 g

Molar mass of H₂O = (2×1) + 16

= 2 + 16

= 18 g/mol

Mass of H₂O from the balanced equation = 2 × 18 = 36 g

SUMMARY

From the balanced equation above,

4 g of H₂ reacted to produce 36 g of H₂O.

Next, we shall determine the mass of H₂ needed to produce 139 kg (i.e 139000 g) of H₂O. This can be obtained as follow:

From the balanced equation above,

4 g of H₂ reacted to produce 36 g of H₂O.

Therefore Xg of H₂ will react to produce 139000 g of H₂O i.e

Xg of H₂ = (4 × 139000)/36

Xg of H₂ = 154444 g

Finally, we shall convert 154444 g to kg this can be obtained as follow:

1000 g = 1 Kg

Therefore,

154444 g = 154444 g × 1 Kg / 1000 g

154444 g = 154.44 Kg

Thus, 154.44 Kg of H₂ is needed to produce 139 Kg of water H₂O