Questions: Calculate the volume in liters of a 0.15 M potassium dichromate solution that contains 350 mmol of potassium dichromate (K2Cr2O7). Round your answer to 2 significant digits.

Calculate the volume in liters of a 0.15 M potassium dichromate solution that contains 350 mmol of potassium dichromate (K2Cr2O7). Round your answer to 2 significant digits.

Transcript text: Calculate the volume in liters of a 0.15 M potassium dichromate solution that contains 350 mmol of potassium dichromate $\left(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\right)$. Round your answer to 2 significant digits.

Solution

Solution Steps

Step 1: Understand the Problem

We need to find the volume of a 0.15 M potassium dichromate solution that contains 350 mmol of potassium dichromate ($\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$).

Step 2: Convert Millimoles to Moles

First, convert 350 mmol to moles. Since 1 mole = 1000 mmol, we have: \[ \text{moles of } \mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7} = \frac{350 \, \text{mmol}}{1000} = 0.35 \, \text{mol} \]

Step 3: Use Molarity to Find Volume

Molarity ($M$) is defined as moles of solute per liter of solution. We can rearrange the formula to find the volume: \[ M = \frac{\text{moles of solute}}{\text{volume in liters}} \] \[ \text{volume in liters} = \frac{\text{moles of solute}}{M} \] Substitute the known values: \[ \text{volume in liters} = \frac{0.35 \, \text{mol}}{0.15 \, \text{M}} = 2.3333 \, \text{L} \]

Step 4: Round to Two Significant Digits

Round the volume to two significant digits: \[ 2.3333 \, \text{L} \approx 2.3 \, \text{L} \]