Answer:
1. The mass of Chlorine pentafluoride, ClF5, is 39.16g
2. The number of mole of Chlorine pentafluoride, ClF5, is 0.3mole
Explanation:
1. To solve the mass of Chlorine pentafluoride, ClF5, first, let us calculate the molar mass of ClF5. This is illustrated below:
Molar Mass of ClF5 = 35.5 + (5 x 19) = 35.5 + 95 = 130.5g/mol
From the ideal gas equation:
PV = nRT (1)
Recall:
Number of mole(n) = mass (m) /Molar Mass(M)
n = m/M
Now substituting the value of n in equation 1, we have:
PV = nRT
PV = mRT/M
Now we can obtain the mass of Chlorine pentafluoride ClF5 as follow:
Data obtained from the question include:
T (temperature) = -17.0 °C = - 17 + 273 = 256K
V (volume) = 35L
P (pressure) = 0.180 atm
R (gas constant) = 0.082atm.L/Kmol
m (mass of Chlorine pentafluoride) =?
M (molar mass of Chlorine pentafluoride) = 130.5g/mol
PV = mRT/M
0.180 x 35 = m x 0.082 x 256/ 130.5
Cross multiply to express in linear form as shown below:
m x 0.082 x 256 = 0.180x35x130.5
Divide both side by 0.082 x 256
m = (0.180x35x130.5) /(0.082x256)
m = 39.16g
Therefore, the mass of Chlorine pentafluoride, ClF5, is 39.16g
2. The number of mole of ClF5 can be obtained as follow:
Mass of ClF5 = 39.16g
Molar Mass of ClF5 = 130.5g/mol
Mole of ClF5 =?
Number of mole = Mass /Molar Mass
Mole of ClF5 = 39.16/130.5g
Mole of ClF5 = 0.3mole
, with 
in our case.