An aqueous solution of glucose is made by disolving 8.75 g of glucose in 100 mL of water. Calculate molarity, molality and the mole fraction
M = mols/L. You get mols by grams/molar mass.
Now that you have mols, you can calculate m.
m = mols/kg solvent.
for X.
You have mols glucose.
Find mols H2O = grams/molar mass
Then total mols = mols glucose+mols H2O
Xglucose = mols glucose/total mols.
Post your work if you get stuck.
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To calculate the molarity of the solution, we need to calculate the number of moles of glucose first and then divide it by the volume of the solution in liters.
Step 1: Calculate the number of moles of glucose.
We can use the formula:
moles = mass / molar mass
The molar mass of glucose (C6H12O6) is as follows:
C = 6 x 12.01 g/mol = 72.06 g/mol
H = 12 x 1.01 g/mol = 12.12 g/mol
O = 6 x 16.00 g/mol = 96.00 g/mol
Therefore, the molar mass of glucose is 180.18 g/mol.
Number of moles of glucose = 8.75 g / 180.18 g/mol = 0.0486 mol
Step 2: Calculate the molarity.
Molarity (M) = moles / volume (in liters)
Given that the volume of the solution is 100 mL, which is equivalent to 0.1 L.
Molarity = 0.0486 mol / 0.1 L = 0.486 M
To calculate the molality of the solution, we need to divide the moles of solute by the mass of solvent (in kg).
Step 1: Calculate the molality.
Molality (m) = moles / mass of solvent (in kg)
Given that the mass of water is 100 mL, and the density of water is 1 g/mL, we can convert the mass of water to kg.
Mass of water = 100 mL x 1 g/mL = 100 g = 0.1 kg
Molality = 0.0486 mol / 0.1 kg = 0.486 mol/kg
To calculate the mole fraction, we need to calculate the moles of solute and the moles of solvent, and then divide the moles of solute by the total moles (solute + solvent).
Step 1: Calculate the moles of solvent.
Moles of solvent (water) = mass of solvent (in grams) / molar mass of water
Molar mass of water (H2O) = 2 x 1.01 g/mol + 16.00 g/mol = 18.02 g/mol
Moles of solvent = 0.1 kg x 1000 g/kg / 18.02 g/mol = 5.54 mol
Step 2: Calculate the mole fraction.
Mole fraction (χ) = moles of solute / (moles of solute + moles of solvent)
Mole fraction = 0.0486 mol / (0.0486 mol + 5.54 mol) = 0.0087
Therefore, the molarity is 0.486 M, the molality is 0.486 mol/kg, and the mole fraction is 0.0087.
To calculate the molarity, molality, and mole fraction of a solution, you need to know the amount of solute (glucose) and the amount of solvent (water).
1. Molarity (M):
Molarity is defined as the number of moles of solute in one liter of solution (moles per liter). To calculate it, you need to convert the mass of glucose into moles and then divide by the volume of the solution in liters.
First, calculate the number of moles of glucose:
Number of moles = mass of glucose (g) / molar mass of glucose (g/mol)
The molar mass of glucose (C6H12O6) is:
(6 * atomic mass of carbon) + (12 * atomic mass of hydrogen) + (6 * atomic mass of oxygen)
Calculate the molar mass and the number of moles of glucose: