A 1% (w/v) solution has how many milligrams per milliliter?

• A. 10 mg/mL
• B. 1 mg/mL
• C. 100 mg/mL
• D. 0.1 mg/mL

Answer: (A)

The concept here is converting percent weight/volume to mg per milliliter. A 1% (w/v) solution means 1 gram in 100 milliliters. Convert to milligrams and to milliliters: 1 g = 1000 mg and 100 mL is the volume. So 1000 mg / 100 mL = 10 mg/mL. Therefore 1% (w/v) equals 10 mg/mL.