What volume of oxygen gas is needed to react completely with 0.626 L of carbon monoxide gas, CO, to form gaseous carbon dioxide? Assume all volume measurements are made at the same temperature and pressure.

0.296L of O₂ are needed for the reaction

Explanation:

This is the reaction:

O₂ + 2CO → 2CO₂

To determine volume, we must work with density. But firstly we have to know the mass.

Density = mass/volume

Ratio is 2:1

CO density = CO mass / CO volume

1.18*10⁻³g/mL = CO mass / 0.626 L

First we must convert 0.626L to mL, because the units of density

0.626L = 626 mL

1.18*10⁻³g/mL = CO mass / 626 mL

CO masa = 1.18*10⁻³g/mL. 626 mL → 0.741 g

Let's convert to moles, the mass of CO (mass. molar mass)

0.741 g / 28 g/mol = 0.0264 moles

As ratio is 2:1, we would need the half of moles, so (0.0264 / 2) = 0.0132 moles are required for the reaction.

Let's convert the moles to mass (molar mass. moles)

32 g/mol. 0.0132 mol = 0.423 g

Now, we can work with oxygen density

O₂ density = O₂ mass / O₂ volume

1.43*10⁻³g/mL = 0.423g / O₂ volume

O₂ volume = 0.423g / 1.43*10⁻³g/mL → 296 mL

296 mL / 1000 = 0.296L