Q: Which of the following correctly expresses the formula for parts per million (ppm) in terms of mass?

$$\text{ppm} = \frac{\text{g of solute}}{\text{g of solution}} \times 10^6$

Q: Which of the following is a correct application of the ppm formula for a solution?

$$\text{ppm} = \frac{\text{g solute}}{\text{g solution}} \times 10^6$

Q: Which of the following is the correct formula for calculating ppb in terms of mass?

$$\text{ppb} = \frac{\text{g solute}}{\text{g solution}} \times 10^9$

Question 1

Which of the following correctly expresses the formula for parts per million (ppm) in terms of mass?

Accepted Answer

$$	ext{ppm} = \frac{	ext{g of solute}}{	ext{g of solution}} 	imes 10^6$

Question 2

A 2.4 L sample of an aqueous solution contains 0.012 mL of NH$$_3. $$What is the concentration of NH$$_3 in $$the solution, expressed as parts per billion (ppb)?

Accepted Answer

500 ppb

Question 3

A 5.12 L sample of solution contains 0.239 g of potassium sulfate, K$$_2SO$_4. If $$the density of the solution is 1.30 g/mL, what is the concentration of K$$_2SO$_4 in $$ppm?

Accepted Answer

28.9 ppm

Question 4

Calculate the concentration in parts per billion (ppb) of an aqueous solution containing 0.91 mg of caffeine in a total volume of 131 mL.

Accepted Answer

0.0069 ppb

Question 5

Glucose makes up about 0.102% by mass of human blood. Calculate this concentration in ppm.

Accepted Answer

0.00102 ppm

Question 6

The average human body contains about 5,000 grams of blood. What mass of arsenic is present in the body if the amount in blood is 0.86 ppb?

Accepted Answer

$$4.3 	imes 10$$^{-3}$$ g

Question 7

A water sample contains the pollutant chlorobenzene with a concentration of 16 ppm (by volume). What volume of this water contains $$5.01 	imes 10$$^{-4}$$ mL of chlorobenzene?

Accepted Answer

$$3.1 	imes 10^4$ mL

Question 8

Which of the following best describes the difference between ppm and ppb?

Accepted Answer

ppm measures concentration per million parts, while ppb measures per billion parts

Question 9

If a solution contains 0.005 g of solute in 5000 g of solution, what is the concentration in ppm?

Accepted Answer

$$1$$ ppm

Question 10

A sample of river water contains 0.002 mg of lead in 2.0 L of water. What is the concentration of lead in ppb?

Accepted Answer

$$1$$ ppb

Question 11

Which of the following is a correct application of the ppm formula for a solution?

Accepted Answer

$$	ext{ppm} = \frac{	ext{g solute}}{	ext{g solution}} 	imes 10^6$

Question 12

A chemist needs to prepare a solution with a concentration of 25 ppm. If she has 2.0 L of water, how many milligrams of solute should she add?

Accepted Answer

50 mg

Question 13

Which of the following statements is true regarding the use of ppm and ppb in medical testing?

Accepted Answer

ppb is used for detecting extremely low concentrations of substances in blood

Question 14

A solution contains 0.003 g of solute in 3.0 L of solution. What is the concentration in ppm, assuming the density of the solution is 1.0 g/mL?

Accepted Answer

$$1$$ ppm

Question 15

If a sample contains 0.0002 g of mercury in 2.0 kg of fish tissue, what is the concentration in ppm?

Accepted Answer

$$0.1$$ ppm

Question 16

A laboratory analysis finds 0.0005 g of a contaminant in 500 mL of water. What is the concentration in ppm?

Accepted Answer

$$1$$ ppm

Question 17

Which of the following is the correct formula for calculating ppb in terms of mass?

Accepted Answer

$$	ext{ppb} = \frac{	ext{g solute}}{	ext{g solution}} 	imes 10^9$

Question 18

A sample of seawater contains 0.0008 g of sodium in 800 mL of water. What is the concentration in ppm?

Accepted Answer

$$1$$ ppm

Parts per Million (ppm) and Parts per Billion (ppb): Concentration Calculations in GOB Chemistry

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