a solution of methanol, CH3OH, contains 55.0 grams of methanol for every 100. grams of water. what is the molality of the solution?
Which is my solvent? And which is my solution? Im confused
USUALLY we call the larger quantity the solvent and the smaller quantity the solute. Also if it's a solid and a liquid we usually call the solid the solute and the liquid the solvent.
I would call the methanol the solute and water the solvent. The solution is the methanol dissolved in the water.
Thank you so much this actually helps alot!!
To determine which component is the solvent and which is the solute, we need to understand the definitions of each.
A solvent is a substance that dissolves another substance, called the solute, forming a solution. It is usually present in a larger amount compared to the solute, and it remains in the same physical state after the formation of the solution.
In the given problem, we have a solution of methanol (CH3OH) and water. To determine which is the solvent and solute, we can look at the amounts given. The problem states that there are 55.0 grams of methanol for every 100 grams of water.
Since methanol is present in a smaller amount (55.0 grams) compared to water (100 grams), we can conclude that methanol is the solute and water is the solvent in this solution.
Now, let's proceed to calculate the molality of the solution.
Molality (m) is defined as the moles of solute per kilogram of solvent. The formula to calculate molality is:
molality (m) = moles of solute / mass of solvent (in kg)
To calculate the molality, we first need to determine the moles of methanol present in the solution. We can do this by using the molar mass of methanol, which is 32.04 g/mol.
Number of moles of methanol = mass of methanol / molar mass of methanol
Number of moles of methanol = 55.0 g / 32.04 g/mol
Next, we need to convert the mass of water into kilograms.
Mass of water (in kg) = mass of water / 1000
Mass of water (in kg) = 100 g / 1000 = 0.1 kg
Now we can calculate the molality using the formula:
molality (m) = moles of solute / mass of solvent (in kg)
molality (m) = (55.0 g / 32.04 g/mol) / 0.1 kg
molality (m) = 1.716 mol / kg
Therefore, the molality of the solution is 1.716 mol/kg.