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How many molecules of water are produced when 8.93 * 10^23 molecules of oxygen are reacted with excess hydrogen gas in the reaction below?

How many molecules of water are produced when 8.93 * 10^23 molecules of oxygen are-example-1
User Radek Suski
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1 Answer

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Step-by-step explanation:

Oxygen gas is reacted with excess hydrogen gas to produce water according to the following equation.

2 H₂ + O₂ ---> 2 H₂O

We have to find the number of molecules of water that are produced when 8.93 * 10^23 molecules of oxygen are reacted.

First we have to convert the molecules of oxygen gas into moles using Avogadro's number. We know that there are 6.022 *10^23 molecules of oxygen in 1 mol of oxygen gas.

1 mol of O₂ = 6.022 *10^23 molecules.

moles of O₂ = 8.93 * 10^23 molecules * 1 mol/(6.022 *10^23 molecules)

moles of O₂ = 1.48 mol

2 H₂ + O₂ ---> 2 H₂O

Now, if we pay attention to the coefficients of the equation, we will see that 2 moles of H₂ will react with 1 mol of O₂ to produce 2 moles of H₂O. That means that the molar ratio between O₂ and H₂O is 1 to 2. We can use that relationship to find the number of moles of H₂O that will be produced by 1.48 moles of O₂ when reacting with excess H₂.

1 mol of O₂ : 2 moles of H₂O molar ratio

moles of H₂O = 1.48 moles of O₂ * 2 moles of H₂O/(1 mol of O₂)

moles of H₂O = 2.96 moles

And finally we can convert the moles of H₂O back to molecules using Avogadro's number again.

1 mol of H₂O molecules = 6.022 * 10^23 molecules

H₂O molecules = 2.96 moles * 6.022 *10^23 molecules/(1 mol)

H₂O molecules = 1.79 * 10^24 molecules

Answer: 1.79 * 10^24 molecules

User Estrar
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