Chapter 8

What is the molarity of a solution prepared with \(0.75\) moles \(\mathrm{NaCl}\) in \(250 . \mathrm{mL}\) solution?

What is the mass percent of an aqueous solution prepared by dissolving \(12.0\) g of solute into \(40.0\) g of water?

What is the volume percent of a solution prepared by adding enough water to 200. mL of acetone to make a total volume of \(1.60 \mathrm{~L} ?\)

What mass of glucose is in \(250.0 \mathrm{~mL}\) of solution that is \(5.00 \%\) by mass? Assume the density of the solution is \(1.00 \mathrm{~g} / \mathrm{mL}\).

For a solution that contains \(25.0 \mathrm{~g}\) of \(\mathrm{NaCl}\) in \(300.0 \mathrm{~mL}\) of water, find each of the following. The density of the water is \(1.00\) \(\mathrm{g} / \mathrm{mL}\). Assume the \(\mathrm{NaCl}\) does not contribute to the volume of the solution a. mass percent b. mass/volume percent

For a solution that contains \(15.0 \mathrm{~mL}\) of methanol \(125 \mathrm{~mL}\) of ethanol, find each of the following. The density of methanol is \(0.792 \mathrm{~g} / \mathrm{mL}\) and the density of ethanol is \(0.789 \mathrm{~g} / \mathrm{mL}\). a. mass percent b. mass/volume percent c. volume percent

A saline solution has a mass percent concentration of \(10.5 \%\). What mass of \(\mathrm{NaCl}\) is present in \(150.0 \mathrm{~mL}\) of the solution? Assume the density of the solution is \(1.00 \mathrm{~g} / \mathrm{mL}\).

Calculate the molarity for each solution. a. \(87.2 \mathrm{~g}\) of \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) in enough water to make \(500 . \mathrm{mL}\) of solution b. \(61.8 \mathrm{~g}\) of \(\mathrm{NH}_{3}\) in enough water to make \(7.00 \mathrm{~L}\) of solution c. 100. \(\mathrm{mL}\) of ethanol \(\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\right)\) in 500. mL of solution (The density of ethanol is \(0.789 \mathrm{~g} / \mathrm{mL}\).)

How many moles of \(\mathrm{KF}\) are contained in \(180.0 \mathrm{~mL}\) of a \(0.250 \mathrm{M}\) solution?

Calculate how many grams of each solute would be required in order to make the given solution. a. \(3.40 \mathrm{~L}\) of a \(0.780 \mathrm{M}\) solution of iron(III) chloride, \(\mathrm{FeCl}_{3}\) b. \(60.0 \mathrm{~mL}\) of a \(4.10 \mathrm{M}\) solution of calcium acetate, \(\mathrm{Ca}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}\)

What volume of a \(0.500 \mathrm{M}\) solution of NaI could be prepared with \(113 \mathrm{~g}\) of solid NaI?

Calculate the molarity of the solutions prepared from the following dilutions. a. \(125 \mathrm{~mL}\) of \(2.00 \mathrm{M} \mathrm{HCl}\) is diluted to a volume of \(4.00 \mathrm{~L}\). b. \(1.85 \mathrm{~mL}\) of \(6.30 \mathrm{M} \mathrm{AgNO}_{3}\) is diluted to a volume of \(5.00 \mathrm{~mL}\).

What volume of \(12 \mathrm{M} \mathrm{HCl}\) is required to prepare \(6.00 \mathrm{~L}\) of a \(0.300 \mathrm{M}\) solution?

What mass of lead is present in \(50.0 \mathrm{~mL}\) of solution with a lead concentration of 12 ppm?

What mass of mercury is present in \(175 \mathrm{~mL}\) of solution with a mercury concentration of \(25 \mathrm{ppb}\) ?

What is the concentration, in units of ppm, for a solution that contains \(34 \mathrm{~g}\) of iron in \(365 \mathrm{~mL}\) of water?

How many equivalents are there in \(2.0\) moles of the ion of each element below? a. magnesium b. aluminum c. sulfur d. bromine (Br) e. cesium (Cs) f. barium (Ba)

How many moles of \(\mathrm{Ca}^{2+}\) are given to a patient if they receive \(250.0 \mathrm{~mL}\) of a solution with a concentration of \(132 \mathrm{mEq} / \mathrm{L} ?\)

A solution contains \(128 \mathrm{mEq} / \mathrm{L}\) of \(\mathrm{Sr}^{2+}\). What volume of solution is needed to have a total mass of \(3.93\) g of strontium ions?

What is chemical equilibrium?

If the reaction \(\mathrm{H}_{2}+\mathrm{I}_{2} \rightleftharpoons 2 \mathrm{HI}\) is at equilibrium, do the concentrations of \(\mathrm{HI}, \mathrm{H}_{2}\), and \(\mathrm{I}_{2}\) have to be equal?

Do the concentrations at equilibrium depend upon how the equilibrium was reached?

What does it mean if the \(\mathrm{K}_{\mathrm{eq}}\) is \(<1\) ?

Define Le Chatelier's principle.

List the three factors types of changes that can disturb the equilibrium of a system.

How will each change affect the reaction? \(\mathrm{PCl}_{5}(g)+\) heat \(\rightleftharpoons \mathrm{PCl}_{3}(g)+\mathrm{Cl}_{2}(g)\) a. Addition of \(\mathrm{PCl}_{5}\) b. Addition of \(\mathrm{Cl}_{2}\) c. Removal of \(\mathrm{PCl}_{3}\) d. Increasing temperature e. Decreasing temperature f. Decreasing volume

How will each change affect the reaction? \(\mathrm{HNO}_{2}(a q) \rightleftharpoons \mathrm{H}^{+}(a q)+\mathrm{NO}_{2}^{-}(a q)\) a. Removal of \(\mathrm{HNO}_{2}\) b. Addition of HCl (i.e. adding more \(\mathrm{H}^{+}\) ) c. Increasing volume d. Decreasing volume e. Removal of \(\mathrm{NO}_{2}^{-}\) f. Addition of \(\mathrm{OH}^{-}\) (which will react with and remove \(\mathrm{H}^{+}\) )

How will each change affect the reaction? \(\mathrm{CO}_{2}(g)+\mathrm{C}(s) \rightleftharpoons 2 \mathrm{CO}(g) \Delta \mathrm{H}=172.5 \mathrm{~kJ}\) a. Addition of \(\mathrm{CO}_{2}\) b. Removal of \(\mathrm{CO}_{2}\) c. Increasing temperature d. Decreasing temperature e. Increasing volume f. Addition of CO

How will each change affect the reaction? \(\mathrm{H}_{2}(g)+\mathrm{I}_{2}(g) \rightleftharpoons 2 \mathrm{HI}(g) \Delta \mathrm{H}=-9.48 \mathrm{~kJ}\) a. Addition of \(\mathrm{H}_{2}\) b. Removal of \(\mathrm{H}_{2}\) c. Increasing temperature d. Decreasing temperature e. Increasing volume f. Decreasing volume

What are some of the features of a semipermeable membrane?

Two solutions are separated by a semipermeable membrane. Solution A contains \(25.0 \mathrm{~g}\) of \(\mathrm{NaCl}\) in \(100.0 \mathrm{~mL}\) of water and solution B contains \(35.0\) g of \(\mathrm{NaCl}\) in \(100.0 \mathrm{~mL}\) of water. a. Which one has a higher concentration? b. Which way will water molecules flow? c. Which volume will increase? d. Which volume will decrease? e. What will happen to the concentration of solution \(\mathrm{A}\) ? f. What will happen to the concentration of solution \(\mathrm{B}\) ?

What do the prefixes hyper, hypo, and iso mean?

Cells are placed in a solution and the cells then undergo hemolysis. What can be said about the relative concentrations of solute in the cell and the solution?

Describe the relative concentrations inside and outside a red blood cell when crenation occurs.

A saltwater fish is placed in a freshwater tank. What will happen to the fish? Describe the flow of water molecules to explain the outcome.

What makes up the "head" region of a phospholipid? Is it hydrophobic or hyrdrophillic?

What makes up the "tail" region of a phospholipid? Is it hydrophobic or hyrdrophillic?

Which statement below is true? Explain. a. All Arrhenius bases are also Brønsted-Lowry bases. b. All Brønsted-Lowry bases are also Arrhenius bases.

Classify each of the following as an acid, base, or neither. a. \(\mathrm{LiOH}\) b. \(\mathrm{HClO}_{4}\) c. \(\mathrm{CH}_{3} \mathrm{COOH}\) d. \(\mathrm{Sr}(\mathrm{OH})_{2}\) e. \(\mathrm{CH}_{4}\) f. \(\mathrm{CH}_{4} \mathrm{OH}\)

What does it mean to say that a substance is amphoteric?

Identify each reactant in the following reactions as an acid or a base according to the Brønsted-Lowry theory. a. \(\mathrm{HIO}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{IO}_{3}^{-}(a q)+\mathrm{H}_{3} \mathrm{O}^{+}(a q)\) b. \(\mathrm{F}^{-}(a q)+\mathrm{HClO}(a q) \rightleftharpoons \mathrm{HF}(a q)+\mathrm{ClO}^{-}(a q)\) ?. \(\mathrm{H}_{2} \mathrm{PO}_{4}^{-}(a q)+\mathrm{OH}^{-}(a q) \rightleftharpoons \mathrm{HPO}_{4}^{2-}(a q)+\mathrm{H}_{2} \mathrm{O}(l)\) d. \(\mathrm{CO}_{3}^{2-}(a q)+\mathrm{H}_{2} \mathrm{O}(l) \rightleftharpoons \mathrm{HCO}_{3}^{-}(a q)+\mathrm{OH}^{-}(a q)\)

Write the formula of each base's conjugate acid. a. \(\mathrm{BrO}_{3}^{-}\) b. \(\mathrm{NH}_{3}\) c. \(\mathrm{CH}_{3} \mathrm{COO}^{-}\) d. \(\mathrm{HCO}_{3}^{-}\) e. \(\mathrm{CN}^{-}\) f. \(\mathrm{HPO}_{4}^{2-}\) g. HS- \(\mathrm{h} . \mathrm{SO}_{4}^{2-}\) i. \(\mathrm{CO}_{3}^{2-}\) \(\mathrm{j} . \mathrm{HCO}_{3}^{-}\) k. \(\mathrm{PH}_{3}\)

Explain why the hydrogen phosphate ion \(\left(\mathrm{HPO}_{4}^{2-}\right)\) is amphoteric.

Describe the process by which water self-ionizes, and explain why pure water is considered to be neutral.

Describe the process by which water self-ionizes, and explain why pure water is considered to be neutral.

Indicate whether solutions with the following \(\mathrm{pH}\) values are acidic, basic, or neutral. a. \(\mathrm{pH}=9.4\) b. \(\mathrm{pH}=7.0\) c. \(\mathrm{pH}=5.0\)

How can the \(\mathrm{pOH}\) of a solution be determined if its \(\mathrm{pH}\) is known? (Hint: Write a mathematical expression.)

Find \(\mathrm{pH}\) and \(\mathrm{pOH}\) of each solution. a. \(\left[\mathrm{H}^{+}\right]=2.3 \times 10^{-4} \mathrm{M}\) b. \(\left[\mathrm{H}^{+}\right]=8.7 \times 10^{-10} \mathrm{M}\) c. \(\left[\mathrm{OH}^{-}\right]=1.9 \times 10^{-9} \mathrm{M}\) d. \(\left[\mathrm{OH}^{-}\right]=0.60 \mathrm{M}\)

Find \(\mathrm{pH}\) and \(\mathrm{pOH}\) of each solution. a. \(\left[\mathrm{H}^{+}\right]=1.0 \times 10^{-5} \mathrm{M}\) b. \(\left[\mathrm{H}^{+}\right]=2.8 \times 10^{-11} \mathrm{M}\) c. \(\left[\mathrm{OH}^{-}\right]=1.0 \times 10^{-2} \mathrm{M}\) d. \(\left[\mathrm{OH}^{-}\right]=4.4 \times 10^{-9} \mathrm{M}\)

Determine \(\left[\mathrm{H}^{+}\right]\) and \(\left[\mathrm{OH}^{-}\right]\) in aqueous solutions with the following \(\mathrm{pH}\) or \(\mathrm{pOH}\) values. a. \(\mathrm{pH}=1.87\) b. \(\mathrm{pH}=11.15\) c. \(\mathrm{pH}=0.95\) d. \(\mathrm{pOH}=6.21\) e. \(\mathrm{pOH}=13.42\) f. \(\mathrm{pOH}=7.03\)