Given the mass of
=25.6 g
The molar mass of
=390.35g/mol
Converting mass of
to moles:

Converting mol
to mol S:

Converting mol S to atoms of S using Avogadro's number:
1 mol = 

Answer:
5 moles of Argon is present in the mixture.
Explanation:
Total pressure of the gaseous mixture = 4 atm
Total number of moles = 16
Partial pressure of Ne = 2.75 atm
By Dalton's law of partial pressure, the total pressure of gaseous mixture is the sum of partial pressures of individual gases which are non-reactive.
Hence:

Also :
Partial pressure = mole fraction*total pressure



∴Number of moles of Argon = 5
Good grief, this stuff got caught in a black hole somewhere. It is terribly dense.
1 mL = 1 cc under normal conditions.
d = mass / volume
m = 20 kg
v = 5 mL
d = 20kg / 5 mL
d = 4 kg / mL
d = 4 kg / cc
A <<<<answer
Answer:
C would be the most best choice for this question.
Thank you.
If you have any questions, feel free to leave a comment and I will get back to it as soon as I can.
-The Spectre
Explanation: