Question

160 mL of water is added to 40 mL of a 1.0 M NaCl solution. What is the final concentration of NaCl?

A) 0.2 M

B) 0.4 M

C) 0.6 M

D) 0.8 M

Answer 1

Upon diluting 40 mL of a 1.0 M NaCl solution with 160 mL of water, the final concentration of NaCl becomes 0.2 M.

Step-by-step explanation:

The question refers to a dilution process involving a sodium chloride (NaCl) solution. The initial volume of the 1.0 M NaCl solution is 40 mL, and 160 mL of water are added, for a final total volume of 200 mL. To find the final concentration of NaCl after dilution, we use the formula M1V1 = M2V2, where M1 and V1 are the initial molarity and volume of the solution, and M2 and V2 are the final molarity and volume of the diluted solution.

Using the formula:
1.0 M * 40 mL = M2 * 200 mL

M2 = (1.0 M * 40 mL) / 200 mL = 0.2 M

Therefore, the final concentration of NaCl after adding 160 mL of water to the 40 mL of 1.0 M NaCl solution is 0.2 M, which corresponds to option A).