0.361g of an unknown liquid occupied a volume of 250.0 ml Hg pressure and 100 degrees celcius. what is the molar mass?
You need to do two things:
1. Clean up your question. I never heard of a liquid occupying a volume of 250 mL Hg pressure.
2. Learn to spell celsius correctly.
To find the molar mass of the unknown liquid, we need to use the ideal gas law equation, PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
First, let’s convert the volume from milliliters (ml) to liters (L) since the ideal gas law equation requires volume in liters. We know that 1 L is equal to 1000 ml, so V = 250.0 ml / 1000 = 0.250 L.
Next, we convert the temperature from Celsius to Kelvin. To do that, we add 273 to the temperature in Celsius, so T = 100 + 273 = 373 K.
Now, we rearrange the ideal gas law equation to solve for the number of moles (n):
n = (PV) / (RT)
Given that the pressure is Hg (mercury) pressure, we need to convert it to atmospheres (atm) because the ideal gas constant (R) is in units of L * atm / (mol * K). One atmosphere (atm) is equal to 760 mmHg (millimeters of mercury), so we can convert the pressure as follows:
P = 250.0 ml Hg / 760 mmHg/atm = 0.329 atm.
Now we can calculate the number of moles (n):
n = (0.329 atm * 0.250 L) / (0.08206 L * atm / (mol * K) * 373 K)
n = 0.0079 mol
Finally, we calculate the molar mass (M) by dividing the mass (m) of the unknown liquid by the number of moles (n):
M = m / n
Given that the mass of the unknown liquid is 0.361 g, we can plug in the values:
M = 0.361 g / 0.0079 mol
Calculating this gives us the molar mass of the unknown liquid.