One easy and valuable conversion unit to memorize is this.
1 ppm = 1 mg/L.
That's all I can help you with since you did not give the substance that was 70 ppm.
Suppose the concentration of sodium in Phoenix tap water is 70 ppm (mass based), then what is the concentration of sodium in milligrams per liter? The density of water is 1 g/mL. The answer units are mg/L.
1 answer