Concept explainers
The units of parts per million (ppm) and parts per billion (ppb) are commonly used by environmental chemists. In general, 1 ppm means 1 part of solute for every 106 parts of solution. Mathematically, by mass:
In the case of very dilute aqueous solutions, a concentration of 1.0 ppm is equal to 1.0 µg of solute per 1.0 mL, which equals 1.0 g solution. Parts per billion is defined in a similar fashion. Calculate the molarity of each of the following aqueous solutions.
a. 5.0 ppb Hg in H2O
b. 1.0 ppb CHCl3 in H2O
c. 10.0 ppm As in H2O
d. 0.10 ppm DDT (C14H9Cl5) in H2O
a)
Interpretation: The molarity of the aqueous solutions has to be calculated.
Concept Introduction: Concentration of solution can be defined in terms of molarity as moles of solute to the volume of solution. The concentration of solution can be given by,
Answer to Problem 121CP
Explanation of Solution
Record the given data
Mass of solute=
Volume of solution=
The mass of the solute and volume of solution are recorded as shown above.
To calculate the molarity of
Molar mass of Hg=
The molarity of
b)
Interpretation: The molarity of the aqueous solutions has to be calculated.
Concept Introduction: Concentration of solution can be defined in terms of molarity as moles of solute to the volume of solution. The concentration of solution can be given by,
Answer to Problem 121CP
Molarity of
Explanation of Solution
Record the given data
Mass of solute=
Volume of solution=
The mass of the solute and volume of solution are recorded as shown above.
To calculate the molarity of
Molar mass of
Molarity of
The molarity of
c)
Interpretation: The molarity of the aqueous solutions has to be calculated.
Concept Introduction: Concentration of solution can be defined in terms of molarity as moles of solute to the volume of solution. The concentration of solution can be given by,
Answer to Problem 121CP
Molarity of
Explanation of Solution
Record the given data
Mass of solute=
Volume of solution=
The mass of the solute and volume of solution are recorded as shown above.
To calculate the molarity of
Molar mass of As=
Molarity of
The molarity of
d)
Interpretation: The molarity of the aqueous solutions has to be calculated.
Concept Introduction: Concentration of solution can be defined in terms of molarity as moles of solute to the volume of solution. The concentration of solution can be given by,
Answer to Problem 121CP
Molarity of
Explanation of Solution
Record the given data
Mass of solute=
Volume of solution=
The mass of the solute and volume of solution are recorded as shown above.
To calculate the molarity of
Molar mass of
Molarity of
The molarity of
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Chapter 4 Solutions
Chemistry
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