Problem 57
The metal cadmium tends to form \(\mathrm{Cd}^{2+}\) ions. The following observations are made: (i) When a strip of zinc metal is placed in \(\mathrm{CdCl}_{2}(a q)\), cadmium metal is deposited on the strip. (ii) When a strip of cadmium metal is placed in \(\mathrm{Ni}\left(\mathrm{NO}_{3}\right)_{2}(a q)\), nickel metal is deposited on the strip. (a) Write net ionic equations to explain each of the observations made above. (b) What can you conclude about the position of cadmium in the activity series? (c) What experiments would you need to perform to locate more precisely the position of cadmium in the activity series?
Problem 58
(a) Use the following reactions to prepare an activity series for the halogens: $$ \begin{aligned} \mathrm{Br}_{2}(a q)+2 \mathrm{NaI}(a q) & \longrightarrow 2 \mathrm{NaBr}(a q)+\mathrm{I}_{2}(a q) \\ \mathrm{Cl}_{2}(a q)+2 \mathrm{NaBr}(a q) & \longrightarrow 2 \mathrm{NaCl}(a q)+\mathrm{Br}_{2}(a q) \end{aligned} $$ (b) Relate the positions of the halogens in the periodic table with their locations in this activity series. (c) Predict whether a reaction occurs when the following reagents are mixed: \(\mathrm{Cl}_{2}(a q)\) and \(\mathrm{KI}(a q) ; \mathrm{Br}_{2}(a q)\) and \(\mathrm{LiCl}(a q)\).
Problem 59
(a) Is the concentration of a solution an intensive or an extensive property? (b) What is the difference between \(0.50 \mathrm{~mol} \mathrm{HCl}\) and \(0.50 \mathrm{M} \mathrm{HCl} ?\)
Problem 60
(a) Suppose you prepare \(500 \mathrm{~mL}\) of a \(0.10 \mathrm{M}\) solution of some salt and then spill some of it. What happens to the concentration of the solution left in the container? (b) Suppose you prepare \(500 \mathrm{~mL}\) of a \(0.10 \mathrm{M}\) aqueous solution of some salt and let it sit out, uncovered, for a long time, and some water evaporates. What happens to the concentration of the solution left in the container? (c) \(\mathrm{A}\) certain volume of a \(0.50 \mathrm{M}\) solution contains \(4.5 \mathrm{~g}\) of a salt. What mass of the salt is present in the same volume of a \(2.50 \mathrm{M}\) solution?
Problem 61
(a) Calculate the molarity of a solution that contains \(0.0250 \mathrm{~mol} \mathrm{NH}_{4} \mathrm{Cl}\) in exactly \(500 \mathrm{~mL}\) of solution. (b) How many moles of \(\mathrm{HNO}_{3}\) are present in \(50.0 \mathrm{~mL}\) of a \(2.50 \mathrm{M}\) solution of nitric acid? (c) How many milliliters of \(1.50 \mathrm{M} \mathrm{KOH}\) solution are needed to provide \(0.275 \mathrm{~mol}\) of KOH?
Problem 62
(a) Calculate the molarity of a solution made by dissolving \(0.750\) grams of \(\mathrm{Na}_{2} \mathrm{SO}_{4}\) in enough water to form exactly \(850 \mathrm{~mL}\) of solution. (b) How many moles of \(\mathrm{KMnO}_{4}\) are present in \(250 \mathrm{~mL}\) of a \(0.0475 \mathrm{M}\) solution? (c) How many milliliters of \(11.6 \mathrm{M} \mathrm{HCl}\) solution are needed to obtain \(0.250 \mathrm{~mol}\) of \(\mathrm{HCl}\) ?
Problem 63
The average adult human male has a total blood volume of \(5.0 \mathrm{~L}\). If the concentration of sodium ion in this average individual is \(0.135 \mathrm{M}\), what is the mass of sodium ion circulating in the blood?
Problem 64
A person suffering from hyponatremia has a sodium ion concentration in the blood of \(0.118 M\) and a total blood volume of \(4.6 \mathrm{~L}\). What mass of sodium chloride would need to be added to the blood to bring the sodium ion concentration up to \(0.138 \mathrm{M}\), assuming no change in blood volume?
Problem 65
The concentration of alcohol \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}\right)\) in blood, called the "blood alcohol concentration" or \(\mathrm{BAC}\), is given in units of grams of alcohol per \(100 \mathrm{~mL}\) of blood. The legal definition of intoxication, in many states of the United States, is that the \(\mathrm{BAC}\) is \(0.08\) or higher. What is the concentration of alcohol, in terms of molarity, in blood if the \(\mathrm{BAC}\) is \(0.08 ?\)
Problem 67
Calculate (a) the number of grams of solute in \(0.250 \mathrm{~L}\) of \(0.175 \mathrm{M} \mathrm{KBr}\), (b) the molar concentration of a solution containing \(14.75 \mathrm{~g}\) of \(\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}\) in \(1.375 \mathrm{~L},(\mathrm{c})\) the volume of \(1.50 \mathrm{M} \mathrm{Na}_{3} \mathrm{PO}_{4}\) in milliliters that contains \(2.50 \mathrm{~g}\) of solute.
