Answer:
The new volume will be 575 mL
Explanation:
Step 1: Data given
Mass of Ar = 125 mg = 0.125 grams
Volume = 505 mL = 0.505 L
Molar mass Ar = 39.95 g/mol
Step 2 : Calculate moles of Ar to start
n = PV/RT
⇒ with n = initial number of moles Ar
⇒ with p = pressure = 1.0 atm
⇒ with R = the gas constant = 0.08206 L* atm/mol *K
⇒ with V = the volume = 0.505 L
⇒ with T = the temperature = 273.15 K
n = 0.505 L * 1 atm / (0.08206 * 273.15 deg K) =0.02253 moles
Step 3: Calculate add moles of Ar
Moles Ar = mass Ar / molar mass Ar
Moles Ar = 0.125 g / 39.95 g/mol = 0.00313 moles
Step 4: Calculate total moles Ar
Total moles Ar = 0.02253 + 0.00313 = 0.02566 moles
Step 5: Calculate new volume
V = nRT/P
V = 0.02566 * 0.08206 * 273.15 / 1 atm
V = 0.575 L = 575 mL
The new volume will be 575 mL
