The molarity of urea in a solution prepared by dissolving 16 g of urea (MW 60.0g/mol) in 39 g of H2O is ______M. The density of the solution is 1.3 g/ml.
you have you add the total grams. so its 16g+39g=55g. so 55g/1.3g/ml=0.0421 L
0.267/.0421=6.3 M
To find the molarity of urea in the solution, we need to first calculate the number of moles of urea and the volume of the solution.
Step 1: Calculate the number of moles of urea.
Moles of urea = Mass of urea / Molecular weight of urea
Moles of urea = 16 g / 60.0 g/mol
Moles of urea = 0.267 mol
Step 2: Calculate the volume of the solution.
Volume of solution = Mass of solution / Density of solution
Volume of solution = (16 g + 39 g) / 1.3 g/ml
Volume of solution = 47 g / 1.3 g/ml
Volume of solution = 36.15 ml
Step 3: Calculate the molarity of urea.
Molarity = Moles of solute / Volume of solution (in liters)
Molarity = 0.267 mol / (36.15 ml x 1 L/1000 ml)
Molarity = 0.267 mol / 0.03615 L
Molarity = 7.38 M
Therefore, the molarity of urea in the solution is 7.38 M.
To find the molarity of the urea solution, we need to calculate the number of moles of urea present in the solution, and then divide it by the volume of the solution in liters.
First, let's calculate the number of moles of urea:
Number of moles = mass / molar mass
Given that the mass of urea is 16 g and the molar mass of urea is 60.0 g/mol, we can calculate:
Number of moles of urea = 16 g / 60.0 g/mol
Next, we need to find the volume of the solution in liters. We can use the given density to do this. Density is defined as mass/volume, so we can rearrange the equation to calculate the volume:
Volume = mass / density
Given that the mass of the solution is 39 g and the density is 1.3 g/mL, we can calculate:
Volume of solution = 39 g / 1.3 g/mL
Now that we have the number of moles of urea and the volume of the solution in liters, we can find the molarity:
Molarity = number of moles / volume of solution
Plugging in the values we calculated, we have:
Molarity = (16 g / 60.0 g/mol) / (39 g / 1.3 g/mL)
To obtain the answer, divide the numerator by the denominator and convert the mL to L by dividing by 1000:
Molarity = (16 / 60) / (39 / 1.3) mol/L
Evaluating the expression, we get:
Molarity ≈ 0.346 M
Therefore, the molarity of the urea solution is approximately 0.346 M.
Moles of solute = 16 g / 60 g/M =
= 0.267 M
volume of H2O = 39g/1.3 g/ml = 30 ml
= 0.03 l
molarity = 0.267 M / 0.03 l
= 8.89 M/l