What is the molarity of a solution of sucrose that has a density of 1.24g/ml and a molecular weight of 342.3g/mol
g sucrose in 1000 mL of the soln =
1.24g/mL x 1000 mL = 1240 grams.
moles = grams/molar mass
and M = moles/L soln.
Thank you DrBob222!
For anyone else with the same problem here is how I did it following the above instructions
d=1.24g/ml
1240g in 1L
1240g/342.3moles=3.6M
thanks angel. i got this too
You are allowed 3 significant figures (1.24) so your answer should be 3.6225M which round to 3 s.f. to 3.62 M.
To find the molarity (M) of a solution, you need to know the amount of solute (in moles) dissolved in a known volume of the solution (in liters).
First, let's calculate the number of moles of sucrose in the solution. To do this, we'll use the given density and molecular weight.
Step 1: Calculate the mass of the solution.
To find the mass of the solution, we need to multiply the density of the solution by the volume of the solution.
Given:
Density of the solution = 1.24 g/mL
Mass of the solution = (Density of the solution) × (Volume of the solution)
Suppose we take a known volume of the solution, let's say 1 liter (1000 mL).
Mass of the solution = 1.24 g/mL × 1000 mL = 1240 g
Therefore, the mass of the solution is 1240 grams.
Step 2: Calculate the number of moles of sucrose.
To determine the number of moles of sucrose, we need to divide the mass of the solute (sucrose) by the molecular weight.
Given:
Molecular weight of sucrose = 342.3 g/mol
Number of moles of sucrose = (Mass of sucrose) ÷ (Molecular weight of sucrose)
Number of moles of sucrose = 1240 g ÷ 342.3 g/mol ≈ 3.6186 mol
Therefore, the number of moles of sucrose in the solution is approximately 3.6186 moles.
Step 3: Calculate the molarity of the solution.
To calculate the molarity, divide the number of moles of sucrose by the volume of the solution in liters.
Given:
Volume of the solution = 1 liter (since we assumed 1000 mL for the volume earlier)
Molarity (M) = (Number of moles of sucrose) ÷ (Volume of the solution in liters)
Molarity (M) = 3.6186 mol ÷ 1 L = 3.6186 M
Therefore, the molarity of the sucrose solution is approximately 3.6186 M.