C.
This is basically the definition of percent composition which is how much mass a element contributes to a specific molecule.
Answer: 37 protons, 48 neutrons, and 36 electrons.
Explanation: I assume "Revision" is Rubidium. It is atomic number 37, so it has 37 protons. It's atomic mass is 85, so it has an average of (85-37) = 48 neutrons. It has a charge of +1, so one electron of the original 37 has left.
<span>Ideal Gas Law is as follows:
PV = nRT
Now lets rearrange so we can get rid of some variables.
V/n = RT/P
Assuming temperature and pressure are the same (atmospheric pressure), we can get:
PV/n = constant (k)
Now since we are dealing with an initial state (2.3 moles, 1.4 liters) lets set that as
V1 and n1 and the final state as V2 and n2
.V1/n1 = constant (k)
V2/n2 = constant (k)
Because the constant is the same (remember me making the assumptions above??)
V1/n1 = V2/n2
now rearrangement:
n1/V1/V2 = 1/n2 -1 = n2
Answer: 11.8 moles are in the final vessel. So to answer the question how much was ADDED, we need to subtract the initial mole number.
11.8 - 2.3 mols = 9.5 mols added</span>
