This is an incomplete question, here is a complete question.
Calculate the volume in milliliters of a 1.29 mol/L iron(II) bromide solution that contains 275 mmol of iron(II) bromide . Round your answer to significant 3 digits.
Answer : The volume of iron(II) bromide solution is, 
Explanation : Given,
Concentration of iron(II) bromide = 1.29 mo/L
Moles of iron(II) bromide = 275 mmol = 0.275 mol
conversion used : 1 mmol = 0.001 mol
Now we have to calculate the volume of iron(II) bromide.

Now put all the given values in this formula, we get:

Thus, the volume of iron(II) bromide solution is, 
Hello!
The ball took up 2,9L
To solve this problem, we should apply the
ideal gas law and clear for n (the number of moles), as this value doesn't change when Devin takes the ball to the garage:

Now, we should clear this equation to find V2, as this is the value we are looking for:

≈2,9L
Have a nice day!
My answer -
hydrogen acceptor any substance ( CYTOCHROME OXIDASE) that can become reduced by the addition of hydrogen, thus enabling the transfer and release of energy as in the ELECTRON TRANSPORT SYSTEM.
P.S
Have an AWESOME!!! day :)