Question

question 15 (1 point) quantities of water and 8.00 mol/l potassium nitrate solution are mixed to produce 700 ml solution with a final concentration of 6.00 mol/l. what volumes of water and potassium nitrate solution are used? 647.5 ml of 8.00 mol/l potassium nitrate and 52.5 ml of water 68.6 ml of 8.00 mol/l potassium nitrate and 631.4 ml of water 525 ml of 8.00 mol/l potassium nitrate and 175 ml of water equal quantities of both

Explanation:

Step1: Let the volume of potassium nitrate solution be $V_1$ and volume of water be $V_2$. We know $V_1 + V_2=700$ mL.

Let $V_1$ be the volume of the 8.00 mol/L potassium nitrate solution and $V_2$ be the volume of water.

Step2: Use the dilution formula $n = C_1V_1 = C_2V$. Here $C_1 = 8.00$ mol/L, $C_2=6.00$ mol/L and $V = 700$ mL.

First, find the number of moles $n$ in the final solution using $n = C_2V$. So $n=6.00\ mol/L\times0.7\ L = 4.2$ mol.

Step3: Then find the volume of the 8.00 mol/L potassium nitrate solution.

Since $n = C_1V_1$, then $V_1=\frac{n}{C_1}=\frac{4.2\ mol}{8.00\ mol/L}=0.525\ L = 525$ mL.

Step4: Find the volume of water.

Since $V_1 + V_2=700$ mL and $V_1 = 525$ mL, then $V_2=700 - 525=175$ mL.

Answer:

525 mL of 8.00 mol/L potassium nitrate and 175 mL of water