Answer:
0.002% w/v
Explanation:
The unit w/v means that mass (in g) per volume (in mL). When the solution is diluted, the mass of the solvent will not change, and the mass can be calculated by the concentration (C) multiplied by the volume (V). So, if 1 is the initial solution, and 2 the diluted solution:
C1*V1 = C2*V2
C1 = 0.02%
V1 = 1 mL
V2 = 10 mL
0.02*1 = C2*10
10C2 = 0.02
C2 = 0.002% w/v