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Multiple Choice
At what temperature in Kelvin does sulfur hexafluoride (SF6) have a density of 0.5550 g/L at a pressure of 0.8210 atm?
A
350 K
B
320 K
C
298 K
D
273 K
Verified step by step guidance
1
Start by using the ideal gas law equation, which is \( PV = nRT \), where \( P \) is pressure, \( V \) is volume, \( n \) is the number of moles, \( R \) is the ideal gas constant, and \( T \) is temperature in Kelvin.
Rearrange the ideal gas law to solve for temperature \( T \): \( T = \frac{PV}{nR} \).
To find \( n \), the number of moles, use the formula \( n = \frac{m}{M} \), where \( m \) is the mass and \( M \) is the molar mass of sulfur hexafluoride (SF6). The molar mass of SF6 is approximately 146.06 g/mol.
Since density \( d \) is given as 0.5550 g/L, use the relationship \( d = \frac{m}{V} \) to express mass \( m \) in terms of density and volume: \( m = dV \). Substitute \( m = dV \) into \( n = \frac{m}{M} \) to get \( n = \frac{dV}{M} \).
Substitute \( n = \frac{dV}{M} \) into the rearranged ideal gas law equation \( T = \frac{PV}{nR} \) to get \( T = \frac{PV}{\frac{dV}{M}R} \). Simplify to \( T = \frac{PM}{dR} \). Now, plug in the values: \( P = 0.8210 \) atm, \( M = 146.06 \) g/mol, \( d = 0.5550 \) g/L, and \( R = 0.0821 \) L atm/mol K, and solve for \( T \).