100mg dissolve in 1000ml what is concentration?

To calculate the concentration, you can use the formula: concentration (C) = mass (m) / volume (V). In this case, 100 mg of a substance dissolved in 1000 mL of solution gives a concentration of 0.1 g/L, since 100 mg equals 0.1 g. This can also be expressed as 100 mg/L.