The space shuttle uses liquid hydrogen and liquid oxygen to produce thrust for liftoff in the following reaction. If the liquid oxygen supply is set to provide 420 kg/s during a launch, what does the rate of liquid hydrogen supply need to be in kilograms per second?
2H₂(l) + O₂(l) $\rightarrow$ 2H₂O(g)

Question

The space shuttle uses liquid hydrogen and liquid oxygen to produce thrust for liftoff in the following reaction. If the liquid oxygen supply is set to provide 420 kg/s during a launch, what does the rate of liquid hydrogen supply need to be in kilograms per second?
2H₂(l) + O₂(l)

\rightarrow

2H₂O(g)

Quizplus · Accepted Answer

From the balanced chemical equation, we can see that for every one mole of oxygen gas consumed, two moles of hydrogen gas are consumed.

We know the rate of oxygen supply is 420 kg/s. To find the rate of hydrogen supply, we need to use the molar ratio from the equation and convert units:

1. Find the molar mass of hydrogen: 
H2 = 2(1.008) = 2.016 g/mol

2. Find the mole ratio of hydrogen to oxygen:
2 mol H2 : 1 mol O2

3. Convert the rate of oxygen supply to moles per second:
420 kg/s / 32 g/mol = 13.125 mol/s

4. Use the mole ratio to find the rate of hydrogen supply:
2 mol H2 / 1 mol O2 * 13.125 mol/s = 26.25 mol/s

5. Convert the rate of hydrogen supply to kilograms per second:
26.25 mol/s * 2.016 g/mol / 1000 = 0.0529 kg/s

Therefore, the rate of liquid hydrogen supply needed is 0.0529 kg/s, which corresponds to choice D.

The Space Shuttle Uses Liquid Hydrogen and Liquid Oxygen to Produce