A solution is composed of 85.5 wt% methanol in water. Find the mol fraction of methanol in the solution.
1 answer:
Answer:
0.7681
Explanation:
Given that the mass percentage of methanol = 85.5 %
which means that 85.5 g of methanol is present in 100 g of the solution.
Thus, mass of water = 100 g - 85.5 g = 14.5 g
The formula for the calculation of moles is shown below:
Mass of methanol = 85.5 g
Molar mass of methanol = 32.04 g/mol
<u>Moles of methanol = 85.5 g / 32.04 g/mol = 2.6685 moles</u>
Mass of water = 14.5 g
Molar mass of methanol = 18 g/mol
<u>Moles of methanol = 14.5 g / 18 g/mol = 0.8056 moles</u>
So, according to definition of mole fraction:
Applying values as:
<u>Mole fraction of methanol in the solution = 0.7681</u>
You might be interested in
Answer:
Statements Y and Z.
Explanation:
The Van der Waals equation is the next one:
(1)
The ideal gas law is the following:
(2)
<em>where n: is the moles of the gas, R: is the gas constant, T: is the temperature, P: is the measured pressure, V: is the volume of the container, and a and b: are measured constants for a specific gas. </em>
As we can see from equation (1), the Van der Waals equation introduces two terms that correct the P and the V of the ideal gas equation (2),<u> by the incorporation of the intermolecular interaction between the gases and the gases volume</u>. The term an²/V² corrects the P of the ideal gas equation since the measured pressure is decreased by the attraction forces between the gases. The term nb corrects the V of the ideal gas equation, <u>taking into account the volume occuppied by the gas in the total volume, which implies</u> a reduction of the total space available for the gas molecules.
So, the correct statements are the Y and Z: the non-zero volumes of the gas particles effectively decrease the amount of "empty space" between them and the molecular attractions between gas particles decrease the pressure exerted by the gas.
Have a nice day!