The molecular weight of glucose is 180.2 and the molecular weight of lactose is 342.3. What is the molarity of a 25% glucose solution? What is the molarity of a 25% lactose solution?
I know that molarity = mol/L or mol/1000 mL and that molecular weight is g/mol. But I'm not sure where to go from there.
If the solution is 25 percent glucose, then
.25(mass glucose+masswater)=mass glucose
So you assume the mass of the water is 1kg. Without density, you really don't know that, so you have to just assume adding glucose doesnt change the volume of the water.
.25massglucose-massglucose=-250kg
massglucose=you do it.
then calc the moles glucose, and you have an approximation for molarity, assuming the volume is still 1liter.
To find the molarity of a solution, we need to know the number of moles of solute (glucose or lactose) and the volume of the solution in liters.
First, let's calculate the number of moles of solute present in the 25% glucose solution.
Step 1: Calculate the mass of glucose in the solution.
Since the solution is 25% glucose, it means that there are 25 grams of glucose in 100 mL of the solution.
Step 2: Convert the mass of glucose to moles.
To convert grams to moles, we need to divide the mass of glucose by its molecular weight. The molecular weight of glucose is 180.2 g/mol.
Number of moles of glucose = (25 g / 180.2 g/mol)
Step 3: Convert the volume in mL to liters.
The volume of the solution is given as 100 mL, which is equivalent to 0.1 liters.
Now, we can calculate the molarity of the 25% glucose solution.
Molarity of glucose = (number of moles of glucose / volume of solution in liters)
Similarly, we can find the molarity of a 25% lactose solution using the same steps:
Step 1: Calculate the mass of lactose in the solution.
Since the solution is 25% lactose, it means that there are 25 grams of lactose in 100 mL of the solution.
Step 2: Convert the mass of lactose to moles.
To convert grams to moles, we need to divide the mass of lactose by its molecular weight. The molecular weight of lactose is 342.3 g/mol.
Number of moles of lactose = (25 g / 342.3 g/mol)
Step 3: Convert the volume in mL to liters.
The volume of the solution is given as 100 mL, which is equivalent to 0.1 liters.
Molarity of lactose = (number of moles of lactose / volume of solution in liters)
By following these steps, you can calculate the molarity of both the 25% glucose and lactose solutions.