Problem
A 2400. -gram sample of an aqueous solution contains 0.012 gram of \( \mathrm{NH}_{3} \). What is the concentration of \( \mathrm{NH}_{3} \) in the solution, expressed as parts per million? 1. \( 5.0 \mathrm{ppm} \) 2. \( 15 \mathrm{ppm} \) 3. 20. ppm 4. 50. ppm
Solution
Step 1 ：\( \frac{0.012 \, \mathrm{grams} \, \mathrm{NH}_{3}}{2400 \, \mathrm{grams} \, \mathrm{solution}} \times 10^{6} = x \, \mathrm{ppm} \)
Step 2 ：\( x = \frac{0.012}{2400} \times 10^{6} \)
Step 3 ：\( x = 5 \, \mathrm{ppm} \)
