If 450.0 mL of a 0.500 M solution is mixed with 200.0 mL of water, what is the molarity of the new

solution?

A. 0.346 M

B. 0.625 M

C. 1. 86 M

D. 2.50 M

Answer: A).346 M

Explanation:

Given:

- 450 mL

-.5 M soln

-200 mL water

1) Convert mL to L

450 mL =.45 L

200 mL =.2 L

2) Find mols in solution

.5 M = x/.45 L

x =.225 mol

3) Find total volume of solution

.45 L +.2 L =.65 L

4) Find new molarity

molarity (M) = mols solute / L solution

y =.225 mol (from step 2) /.65 L (from step 3)

y =.346 M

Answer: A).346 M