How many moles of urea (60.g/mol)must be dissolved in 66.6g of water to give a 2.4 m solution? A)1.4 × 10² mol B)2.4 mol C)0.0024 mol D)0.15 mol E)9.0 × 10² mol

Question

Quizplus · Accepted Answer

First, we need to convert the molarity (2.4 M) to moles of solute per liter of solution. 
2.4 M = 2.4 mol/L

Next, we need to find the volume of the solution that contains the desired amount of moles of solute. 
2.4 mol/L x V = moles of solute

To find V, rearrange the equation: 
V = moles of solute / 2.4 mol/L

Now we can plug in the values we know: 
moles of solute = (66.6 g water) x (1 mol/18.015 g) x (2.4 mol/L) 
moles of solute = 8.8 mol

V = 8.8 mol / 2.4 mol/L 
V = 3.67 L

Since we want to prepare a solution that only contains 66.6 g of water, we need to adjust the amount of solute accordingly. We can use the following proportion:

8.8 mol : 3.67 L = x mol : 0.0666 L

Solving for x: 
x = (0.0666 L)(8.8 mol) / (3.67 L) 
x = 0.159 mol

Therefore, we need 0.159 mol of urea to be dissolved in 66.6 g of water to prepare a 2.4 M solution. This is equivalent to 0.159 mol / 60 g/mol = 0.00265 kg or 2.65 g of urea. 
The closest answer choice to this value is D) 0.15 mol.

How Many Moles of Urea (60