Chapter 14

What factors must be considered when creating a dilute solution from a stock solution?

How do 0.5\(M\) and 2.0\(M\) aqueous solutions of NaCl differ?

Under what conditions might a chemist describe a solution in terms of molality? Why?

According to lab procedure, you stir 25.0 \(\mathrm{g}\) of \(\mathrm{MgCl}_{2}\) into 550 \(\mathrm{mL}\) of water. What is the percent by mass of \(\mathrm{MgCl}_{2}\) in the solution?

How many grams of LiCl are in 275 g of a 15\(\%\) aqueous solution of LiCl?

Calculate the percent by volume of a solution created by adding 75 \(\mathrm{mL}\) of acetic acid to 725 \(\mathrm{mL}\) of water.

Calculate the molarity of a solution that contain 15.7 \(\mathrm{g}\) of \(\mathrm{CaCO}_{3}\) dissolved in 275 \(\mathrm{mL}\) of water.

How many moles of BaS would be used to make \(1.5 \times 10^{3} \mathrm{mL}\) of a 10.0 \(\mathrm{M}\) solution?

How much \(\mathrm{CaCl}_{2},\) in grams, is needed to make 2.0 \(\mathrm{L}\) of a 3.5\(M\) solution?

Experiment In the lab, you dilute 55 \(\mathrm{mL}\) of a 4.0 \(\mathrm{M}\) solution to make 250 \(\mathrm{mL}\) of solution. Calculate the molarity of the new solution.

How many milliliters of 3.0\(M\) phosphoric acid \(\left(\mathrm{H}_{3} \mathrm{PO}_{4}\right)\) can be made from 95 \(\mathrm{mL}\) of a 5.0 \(\mathrm{M} \mathrm{H}_{3} \mathrm{PO}_{4}\) solution?

If you dilute 20.0 \(\mathrm{mL}\) of a 3.5 \(\mathrm{M}\) solution to make 100.0 \(\mathrm{mL}\) of solution, what is the molarity of the dilute solution?

What is the molality of a solution that contain 75.3 \(\mathrm{g}\) of \(\mathrm{KCl}\) dissolved in 95.0 \(\mathrm{g}\) of water?

How many grams of \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) must be dissolved into 155 \(\mathrm{g}\) of water to create a solution with a molality of 8.20 \(\mathrm{mol} / \mathrm{kg}\) ?

What is the molality of a solution containing 30.0 \(\mathrm{g}\) of naphthalene \(\left(\mathrm{C}_{10} \mathrm{H}_{8}\right)\) dissolved in 500.0 \(\mathrm{g}\) of toluene?

What are the molality and mole fraction of solute in a 35.5 percent by mass aqueous solution of formic acid \((\mathrm{HCOOH}) ?\)

What are three ways to increase the rate of solvation?

Explain the difference between saturated and unsaturated solutions.

At a pressure of 1.5 atm, the solubility of a gas is 0.54 g/L. Calculate the solubility when the pressure is doubled.

At 4.5 atm of pressure, the solubility of a gas is 9.5 g/L. How much gas, in grams, will dissolve in 1 L if the pressure is reduced by 3.5 atm?

The solubility of a gas at 37.0 \(\mathrm{kPa}\) is 1.80 \(\mathrm{g} / \mathrm{L}\) . At what pressure will the solubility reach 9.00 \(\mathrm{g} / \mathrm{L} ?\)

Soft Drinks The partial pressure of \(\mathrm{CO}_{2}\) inside a bottle of soft drink is 4.0 \(\mathrm{atm}\) at \(25^{\circ} \mathrm{C}\) . The solubility of \(\mathrm{CO}_{2}\) is 0.12 \(\mathrm{mol} / \mathrm{L}\) . When the bottle is opened, the partial pressure drops to \(3.0 \times 10^{-4} \mathrm{atm} .\) What is the solubility of \(\mathrm{CO}_{2}\) in the open drink? Express your answer in grams per liter.

Define the term colligative property.

Identify each variable in the following formula: $$\Delta T_{\mathrm{b}}=K_{\mathrm{b}} m$$

Define the term osmotic pressure, and explain why it is considered a colligative property.

Apply your knowledge of polarity and solubility to predict whether solvation is possible in each situation shown in Table \(14.9 .\) Explain your answers. \(\begin{array}{ll}{\text {Solute}} & {\text {Solvent}} \\ {\text { solid } \mathrm{MgCl}_{2}} & {\text { liquid } \mathrm{H}_{2} \mathrm{O}} \\ {\text { liquid } \mathrm{NH}_{3}} & {\text { liquid } \mathrm{C}_{6} \mathrm{H}_{6}} \\\ {\text { gaseous } \mathrm{H}_{2}} & {\text { liquid } \mathrm{H}_{2} \mathrm{O}} \\ {\text { liquid } \mathrm{I}_{2}} & {\text { liquid } \mathrm{Br}_{2}} \end{array}\)

Household Paint Some types of paint are colloids composed of pigment particles dispersed in oil. Based on what you know about colloids, recommend an appropriate location for storing cans of leftover household paint. Justify your recommendation.

Which solute has the greatest effect on the boiling point of 1.00 \(\mathrm{kg}\) of water: 50.0 \(\mathrm{g}\) of strontium chloride \(\left(\mathrm{Sr} \mathrm{Cl}_{2}\right)\) or 150.0 \(\mathrm{g}\) of carbon tetrachloride (CCl \(_{4} ) ?\) Justify your answer.

If you prepared a saturated aqueous solution of potassium chloride at \(25^{\circ} \mathrm{C}\) and then heated it to \(50^{\circ} \mathrm{C},\) would you describe the solution as unsaturated, saturated, or supersaturated? Explain.

How many grams of calcium nitrate (Ca(NO \(_{3} )_{2} )\) would you need to prepare 3.00 L of a 0.500\(M\) solution?

Develop a plan for making 1000 \(\mathrm{mL}\) of a 5\(\%\) by volume solution of hydrochloric acid in water. Your plan should describe the amounts of solute and solvent necessary, as well as the steps involved in making the solution.

Infer Dehydration occurs when more fluid is lost from the body than is taken in. Scuba divers are advised to hydrate their bodies before diving. Use your knowledge of the relationship between pressure and gas solubility to explain the importance of hydration prior to a dive.

Design an Experiment You are given a sample of a solid solute and three aqueous solutions containing that solute. How would you determine which solution is saturated, unsaturated, and supersaturated?

Compare Which of the following solutions has the highest concentration? Rank the solutions from the greatest to the smallest boiling point depression. Explain your answer. a. 0.10 mol \(\mathrm{NaBr}\) in 100.0 \(\mathrm{mL}\) solution b. 2.1 \(\mathrm{mol} \mathrm{KOH}\) in 1.00 \(\mathrm{L}\) solution c. 1.2 \(\mathrm{mol} \mathrm{KMnO}_{4}\) in 3.00 \(\mathrm{L}\) solution

The radius of an argon atom is 94 \(\mathrm{pm}\) . Assuming the atom is spherical, what is the volume of an argon atom in cubic nanometers? \(V=4 / 3 \pi r^{3}\) (Chapter 3\()\)

Identify which molecule is polar. (Chapter 8) \(\begin{array}{ll}{\text { a. } \operatorname{SiH}_{4}} & {\text { c. } \mathrm{H}_{2} \mathrm{S}} \\ {\text { b. } \mathrm{NO}_{2}} & {\text { d. } \mathrm{NCl}_{3}}\end{array}\)

Name the following compounds. (Chapter 7) a. NaBr b. \(\operatorname{Pb}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\) c. \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}\)

A 12.0 -g sample of an element contains \(5.94 \times 10^{22}\) atoms. What is the unknown element? (Chapter 10\()\)

Pure bismuth can be produced by the reaction of bismuth oxide with carbon at high temperatures. $$2 \mathrm{Bi}_{2} \mathrm{O}_{3}+3 \mathrm{C} \rightarrow 4 \mathrm{Bi}+3 \mathrm{CO}_{2}$$ How many moles of \(\mathrm{Bi}_{2} \mathrm{O}_{3}\) reacted to produce 12.6 \(\mathrm{mol}\) of \(\mathrm{CO}_{2} ?(\text {Chapter } 11)\)

Are dissolved oxygen values most closely related to latitude or longitude? Why do you think this is true?