Respuesta :
Answer: The mass and number of moles of sulfur hexafluoride gas is 2.8 g and 0.019 moles respectively.
Explanation:
To calculate the moles of sulfur hexafluoride gas, we use the equation given by ideal gas:
PV = nRT
where,
P = Pressure of sulfur hexafluoride = 0.090 atm
V = Volume of the sulfur hexafluoride gas = 5.0 L
n = number of moles of gas = ?
R = Gas constant = [tex]0.0821\text{ L. atm }mol^{-1}K^{-1}[/tex]
T = Temperature of sulfur hexafluoride gas = [tex]14^oC=[273+14]K=287K[/tex]
Putting values in above equation, we get:
[tex]0.090atm\times 5.0L=n\times 0.0821\text{ L. atm }mol^{-1}K^{-1}\times 287K\\\\n=0.019mol[/tex]
To calculate the mass of sulfur hexafluoride, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Molar mass of sulfur hexafluoride = 146.0 g/mol
Moles of sulfur hexafluoride = 0.0191 moles
Putting values in equation 1, we get:
[tex]0.019mol=\frac{\text{Mass of sulfur hexafluoride}}{146.0g/mol}\\\\\text{Mass of sulfur hexafluoride}=2.8g[/tex]
In case of multiplication and division, the number of significant digits is taken from the value which has least precise significant digits. Here, the least precise number of significant digits are 2.
Hence, the mass and number of moles of sulfur hexafluoride gas is 2.8 g and 0.019 moles respectively.
