Answer
For He(g): 1.87 atm
For Ne(g) = 0.8085 atm
For Ar(g) = 0.2695 atm
Work Step by Step
To find the partial pressure of each gas we can perform PV = nRT with each of the different quantities of moles since the partial pressures are independent of one another. First we convert the 25C to Kelvin by adding 273 = 298K.
Then we have
P = nRT / V but since T and V will stay constant, we will find the value of (RT/V)
RT/V = (0.0821 * 298K) / 10L = 2.45
Then for each gas we have:
P = n * (RT/V) so for He(g) we have P = 0.765mol * 2.45 = 1.87 atm
for Ne(g) we have P = 0.330 mol * 2.45 = 0.8085 atm
for Ar(g) we have P = 0.110 * 2.45 = 0.2695 atm