CHEM 253 PROBLEMS: UNITS AND CONCENTRATIONS Courtesy of Dr.
Ray von Wandruszka
1.
2.
How many grams of sodium chloride are contained in (or are necessary to
prepare) 500 mL of normal saline, which is 0.85 %, (w/v)?
(a) One liter of a 5.0 % (w/v) solution of glucose contains how many grams of
glucose?
(b) One gallon (3,800 mL) of a 10-ppm solution of ethyl alcohol contains how
many milligrams of ethyl alcohol?
3.
Express the percent by weight of a solution that weighs 200 g and contains 25.0
g of sodium sulfate.
4.
Calculate the percent by volume of a solution prepared by adding 50.0 mL of
methanol to 200 mL of water. Assume that the volumes are additive.
5.
Calculate the percent by weight of a solution prepared by dissolving 5.00 g of
silver nitrate in 100 mL of water. Assume that the density of water is 1.00. (Note
that this problem cannot be solved unless the density of the solvent is known.)
6.
What volumes of concentrated acetic acid and of water would be used to
prepare 300 mL of 1:5 solution?
7.
A solution of sulfuric acid (MW, 98.0) contains 4.90 g of H2S04 in 400 mL.
Calculate the molar concentration.
8.
How many grams of silver nitrate (MW, 169.9) are necessary to prepare 500
mL of 0.1250 M solution?
9.
What is the molar concentration of a 0.85% (w/v) solution of sodium chloride
(MW, 58.4)?
10.
How many millimoles are present in 150 mL of a 0.025 M solution?
11.
How many grams of sodium sulfate (MW, 142.0; eq wt, 71.00) are necessary to
prepare 200.0 mL of a 0.5000 N solution for precipitation reactions?
12.
Calculate the molarity for neutralization reactions of a solution of sodium
hydroxide (MW, 40.00; eq wt, 40.00) prepared by dissolving 100.0 g of sodium
hydroxide in sufficient water to make 1000 mL of solution.
13.
How many grams of silver nitrate (MW, 169.9) are necessary to prepare 500.0
mL of a solution of which 1 mL would precipitate (as AgCl) with exactly 0.5000
mg of chloride (at wt, 35.45)?
Chem 253 Introduction
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CHEM 253 Answers to Problems: Units & Concentration
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Chem 253 Introduction
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