Question

a chemist must prepare 525 ml of 1.00 m aqueous barium - chloride (bacl₂) working solution. hell do this by pouring out some 1.30 mol/l aqueous barium chloride stock solution into a graduated cylinder and diluting it with distilled water. calculate the volume in ml of the barium - chloride stock solution that the chemist should pour out. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Identify the dilution formula

The dilution formula is $M_1V_1 = M_2V_2$, where $M_1$ is the molarity of the stock solution, $V_1$ is the volume of the stock solution, $M_2$ is the molarity of the working - solution, and $V_2$ is the volume of the working - solution.

Step2: Assign the given values

We are given that $M_1=1.30\ M$, $M_2 = 1.00\ M$, and $V_2=525\ mL$. We need to find $V_1$.

Step3: Rearrange the formula to solve for $V_1$

From $M_1V_1 = M_2V_2$, we can solve for $V_1$ as $V_1=\frac{M_2V_2}{M_1}$.

Step4: Substitute the values into the formula

$V_1=\frac{1.00\ M\times525\ mL}{1.30\ M}$.

Step5: Calculate the result

$V_1=\frac{525}{1.30}\ mL\approx404\ mL$ (rounded to three significant figures).

Answer:

404 mL