Practice Calculations Involving Percent Composition And Ppm/ppb (1.4.3)

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6 sample questions

Question 1.
Calculate the percent composition of oxygen in H₂O, given that the molar mass of water is 18.02 g/mol.
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Use the formula for percent composition.
Question 2.
What does 2.0 ppm mean in terms of mass?
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Remember the definition of ppm.
3Question 3.
What formula is used to calculate percent by mass?
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Think about how to express a fraction as a percentage.
4Question 4.
1 ppm is equivalent to ____ mg of solute in 1 kg of solution.
- 1 mg
- 0.01 mg
- 1000 mg
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Recall the definition of ppm.
Question 5.
A solution contains 4.5 g of sodium chloride in 600 g of solution. Calculate the percent by mass of sodium chloride, and then determine its ppm in the same solution.
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Use the definitions for both percent mass and ppm to guide your calculations.
Question 6.
A water sample has 0.012 g of a contaminant in 2 kg of water. Calculate the concentration in both ppm and ppb.
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Convert all masses to the appropriate units before applying the formulas.

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