___ equals 10,000 mg/L.

• A. 0.01%
• B. 1%
• C. 0.1%
• D. 0.001%

Answer: (B)

Converting percent concentration to mg/L uses the idea that a percent (by weight/volume) means grams per 100 milliliters. So 1% means 1 g in 100 mL. In one liter (which is 1000 mL), that scales to 10 g per liter. 10 g is 10,000 mg, so 1% corresponds to 10,000 mg/L. The other percentages give smaller amounts per liter: 0.01% is 0.1 g per liter (100 mg/L), 0.1% is 1 g per liter (1,000 mg/L), and 0.001% is 0.01 g per liter (10 mg/L). Therefore, the statement that equals 10,000 mg/L is the 1% case.