A 54.0 mL aliquot of a 1.60 M solution is diluted to a total volume of 218 mL. A 109 mL portion of that solution is diluted by adding 161 mL of water. What is the final concentration? Assume the volumes are additive g

The final concentration is 0.16 M.

Explanation:

According to the dilution law:

where,

= molarity of stock solution = 1.60 M

= volume of stock  solution = 54.0 ml

= molarity of diluted solution = ?

= volume of diluted solution = 218 ml

Putting these values:

Now 109 ml of this diluted solution is further diluted by adding 161 mL of water.

Again applying dilution law:

Thus the final concentration is 0.16 M

the answer is d. 74.02