The acceptable limit for nitrate, often found in well water in agricultural areas, is 10 ppm. If a water sample is found to contain 355 µg/L, determine the concentration in parts per million, ppm. Express your answer in decimal form rounded to the third decimal place. Do not include units with your answer.

A good conversion factor to remember when dealing with ppm and ppb is

1 ppm = 1 mg/L
so if you have 355 ug/L that is 0.355 mg/L = 0.355 ppm.

To determine the concentration in parts per million (ppm), we need to convert the given concentration in micrograms per liter (µg/L) to milligrams per liter (mg/L), and then to parts per million (ppm).

1. Convert from µg/L to mg/L:
To convert micrograms to milligrams, divide the given concentration by 1000.
355 µg/L / 1000 = 0.355 mg/L

2. Convert from mg/L to ppm:
To convert milligrams per liter to parts per million, multiply the concentration by 1000.
0.355 mg/L × 1000 = 355 ppm

Therefore, the concentration of nitrate in the water sample is 355 ppm.