Question

Two solutions were mixed: 200 mL of 0.5 M NaOH and 500 mL of 0.7 M HCl. Calculate molarity for each solute in the final solution.

Answer 1

The molarity of NaOH in the final solution is 0.143 M, and the molarity of HCl in the final solution is 0.5 M.

Step-by-step explanation:

To calculate the molarity of each solute in the final solution, we need to use the formula:

Molarity = moles of solute / volume of solution in liters

First, let's calculate the moles of NaOH and HCl in their respective solutions:

moles of NaOH = concentration of NaOH * volume of NaOH solution

= 0.5 M * 0.2 L

= 0.1 moles

moles of HCl = concentration of HCl * volume of HCl solution

= 0.7 M * 0.5 L

= 0.35 moles

Next, let's calculate the total volume of the final solution by adding the volumes of the two solutions:

total volume of final solution = 0.2 L + 0.5 L

= 0.7 L

To calculate the molarity of NaOH and HCl in the final solution, we need to calculate the total moles of each solute in the final solution:

total moles of NaOH = moles of NaOH in 200 mL solution

= 0.1 moles

total moles of HCl = moles of HCl in 500 mL solution

= 0.35 moles

Now, we can calculate the molarity of each solute in the final solution:

Molarity of NaOH = total moles of NaOH / total volume of final solution

= 0.1 moles / 0.7 L

= 0.143 M

Molarity of HCl = total moles of HCl / total volume of final solution

= 0.35 moles / 0.7 L

= 0.5 M

Therefore, the molarity of NaOH in the final solution is 0.143 M, and the molarity of HCl in the final solution is 0.5 M.