Question

what are the proper units for molar concentration, m? l/mole mole/l mole/ml mole/kl question 9 1 pts which equation below give the proper units for the molarity of a sucrose solution composed of 0.133 moles of sucrose in 355 ml of water? use dimensional analysis of the units to identify the correct equation: m = mole/liter m = molsolute/lsolution = 0.133 mol×355 ml / (1 l / 1000 ml) m = molsolute/lsolution = 0.133 mol / (355 ml×(1 l / 1000 ml)) m = molsolute/lsolution = 355 ml / (0.133 mol×(1 l / 1000 ml)) m = molsolute/lsolution = (355 ml×(1 l / 1000 ml)) / 0.133 mol

Explanation:

Step1: Recall molar - concentration definition

Molarity (M) is defined as the number of moles of solute per liter of solution, i.e., $M=\frac{\text{moles of solute}}{\text{liters of solution}}$. So the unit of molar concentration is mole/L.

Step2: Analyze dimensional - analysis for second question

We have 0.133 moles of solute (sucrose) and 355 mL of solution. First, convert the volume from mL to L. Since 1 L = 1000 mL, the volume in L is $V = 355\ mL\times\frac{1\ L}{1000\ mL}$. Molarity $M=\frac{\text{moles of solute}}{\text{liters of solution}}=\frac{0.133\ mol}{355\ mL\times\frac{1\ L}{1000\ mL}}$.

Answer:

For the first question: mole/L
For the second question: $M=\frac{\text{molsolute}}{\text{Lsolution}}=\frac{0.133\ mol}{355\ mL\times\frac{1\ L}{1000\ mL}}$