The Components of Matter

A concentration cell consists of two H2/H half-cells. Half cell A has H2 $\mathbf{0}\mathbf{.}\mathbf{95}$ atm bubbling into $\mathbf{0}\mathbf{.}\mathbf{10}$ M HCl. Half-cell B has H2 at $\mathbf{0}\mathbf{.}\mathbf{60}$atm bubbling into $\mathbf{2}\mathbf{.}\mathbf{0}$M HCl. Which half-cell houses the anode? What is the voltage of the cell?

Show three units of a linear silicone polymer made from $\mathbf{(}\mathbf{C}{\mathbf{H}}_{\mathbf{3}}{\mathbf{)}}_{\mathbf{2}}\mathbf{Si}{\left(\mathbf{OH}\right)}_{\mathbf{2}}$with some  ${\left({\mathbf{CH}}_{\mathbf{3}}\right)}_{\mathbf{3}}\mathbf{SiOH}$added to the end chain.

Consider the following reaction:

$\mathbf{\text{2NOBr(g) }}\mathbf{\rightleftharpoons }{\mathbf{\text{2NO(g) + Br}}}_{\mathbf{\text{2}}}\mathbf{\text{(g)}}\mathbf{ }$

  $\mathit{K}\mathbf{ }\mathbf{=}\mathbf{ }\mathbf{0}\mathbf{.}\mathbf{42}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{373}\mathit{K}$

Given that  ${\mathit{S}}^{\mathbf{°}}\mathbf{ }\mathit{o}\mathit{f}\mathbf{ }\mathit{N}\mathit{O}\mathit{B}\mathit{r}\left(g\right)\mathbf{=}\mathbf{272}\mathbf{.}\mathbf{6}\mathit{k}\mathit{J}\mathbf{/}\mathit{m}\mathit{o}\mathit{l}\mathbf{\times }\mathit{K}$  and that$\mathbf{∆}{\mathit{S}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{ }\mathit{a}\mathit{n}\mathit{d}\mathbf{ }\mathbf{∆}{\mathit{H}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}$   are constant with temperature, find

$$\begin{gathered} \mathbf{\left(}\mathit{a}\mathbf{\right)}\mathbf{∆}{\mathit{S}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{298}\mathit{K} \\ \mathbf{\left(}\mathit{b}\mathbf{\right)}\mathbf{∆}{\mathit{G}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{373}\mathit{K} \\ \mathbf{\left(}\mathit{c}\mathbf{\right)}\mathbf{ }\mathbf{∆}{\mathit{H}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{373}\mathit{K} \\ \mathbf{\left(}\mathit{d}\mathbf{\right)}\mathbf{ }\mathbf{∆}{\mathit{H}}_{\mathbf{f}}^{\mathbf{°}}\mathbf{ }\mathit{o}\mathit{f}\mathbf{ }\mathit{N}\mathit{O}\mathit{B}\mathit{r}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{298}\mathit{K} \\ \mathbf{\left(}\mathit{e}\mathbf{\right)}\mathbf{∆}{\mathit{G}}_{\mathbf{\gamma }\mathbf{g}\mathbf{n}}^{\mathbf{°}}\mathit{a}\mathit{t}\mathbf{ }\mathbf{298}\mathit{K} \\ \mathbf{\left(}\mathit{f}\mathbf{\right)}\mathbf{ }\mathbf{∆}{\mathit{G}}_{\mathbf{f}}^{\mathbf{°}}\mathbf{ }\mathit{o}\mathit{f}\mathbf{ }\mathit{N}\mathit{O}\mathit{B}\mathit{r}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{298}\mathit{K} \end{gathered}$$

Rank the following oxides in order of increasing acidity in water: ${\mathbf{Sb}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{3}}\mathbf{,}{\mathbf{Bi}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{3}}\mathbf{,}{\mathbf{P}}_{\mathbf{4}}{\mathbf{O}}_{\mathbf{10}\mathbf{,}}{\mathbf{Sb}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{5}}$

Calculate the equilibrium constants for decomposition of the hydrogen halides at  :

 $\mathbf{\text{2HX(g)}}\mathbf{\rightleftharpoons }{\mathbf{\text{H}}}_{\mathbf{\text{2}}}{\mathbf{\text{(g) + X}}}_{\mathbf{\text{2}}}\mathbf{\text{(g)}}$

What do these values indicate about the extent of decomposition of $\mathit{H}\mathit{X}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{298}\mathit{K}\mathbf{?}$ Suggest a reason for this trend.

Hydrogenation is the addition of${\mathit{H}}_{\mathbf{2}}$   to double (or triple) carbon-carbon bonds. Peanut butter and most commercial baked goods include hydrogenated oils. Find   $\mathbf{∆}{\mathit{H}}^{\mathbf{°}}\mathbf{,}\mathbf{ }\mathbf{∆}{\mathit{S}}^{\mathbf{°}}\mathbf{ }\mathit{a}\mathit{n}\mathit{d}\mathbf{ }\mathbf{∆}{\mathit{G}}^{\mathbf{°}}$for the hydrogenation of ethene    to ethane$\left(C_2{H}_6\right)$   at${\mathbf{25}}^{\mathbf{°}}\mathit{C}$  .

Assuming acid strength relates directly to a number of $\mathbf{O}$ atoms bonded to the central atom, rank ${\mathbf{H}}_{\mathbf{2}}{\mathbf{N}}_{\mathbf{2}}{\mathbf{O}}_{\mathbf{2}}$  $[\mathrm{or} {\left(\mathrm{HON}\right)}_2]$; ${\mathbf{HNO}}_{\mathbf{3}}\mathbf{ }\left(\mathrm{or} {\mathrm{HONO}}_2\right)$; and ${\mathbf{HNO}}_{\mathbf{2}}\left(\mathrm{or} \mathrm{HONO}\right)$ in order of decreasing acid strength.

Styrene is produced by catalytic dehydrogenation of ethylbenzene at high temperature in the presence of superheated steam.

 (a) Find  $\mathbf{∆}{\mathit{H}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{,}\mathbf{ }\mathbf{∆}{\mathit{G}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{ }\mathit{a}\mathit{n}\mathit{d}\mathbf{ }\mathbf{∆}{\mathit{S}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}$ given these data at $\mathbf{298}\mathit{K}$ :

 (b) At what temperature is the reaction spontaneous?

 (c) What are $\mathbf{∆}{\mathit{G}}_{\mathbf{\gamma }\mathbf{N}\mathbf{n}}^{\mathbf{°}}$  and ${\mathbf{600}}^{\mathbf{°}}\mathit{C}$ ?

  (d) With  $\mathbf{5}\mathbf{.}\mathbf{0}$ parts steam to  $\mathbf{1}\mathbf{.}\mathbf{0}$ part ethylbenzene in the reactant mixture and the total pressure kept constant at$\mathbf{1}\mathbf{.}\mathbf{3}\mathit{a}\mathit{t}\mathit{m}$  what is $\mathbf{∆}\mathit{G}$$\mathit{a}\mathit{t}\mathbf{ }\mathbf{50}\mathbf{\%}$ conversion, that is, when $\mathbf{50}\mathbf{\%}$  of the ethylbenzene has reacted?

Bromine monochloride is formed from the elements:  

$\mathbf{∆}{\mathit{H}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{=}\mathbf{-}{\mathbf{\text{1.35 kJ/mol ∆G}}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{\text{=-0.88 kJ/mol}}$

Calculate 

(a)   $\mathbf{∆}{\mathit{H}}_{\mathbf{f}}^{\mathbf{°}}$and 

(b)   ${\mathit{S}}^{\mathbf{°}}$of  $\mathbf{\text{BrCl(g)}}$

Calculate each of the following quantities: (a) Grams of solute needed to make 475 mL of 5.62×10^-2 M potassium sulfate (b) Molarity of a solution that contains 7.25 mg of calcium chloride in each milliliter (c) Number of Mg²⁺ ions in each milliliter of 0.184 M magnesium bromide.

Find $\mathit{K}$for

(a) the hydrolysis of ATP, 

(b) the dehydration condensation to form glucose phosphate, and 

(c) the coupled reaction between ATP and glucose. 

(d) How does each  $\mathit{K}$ change when $\mathit{T}$  changes from ${\mathbf{25}}^{\mathbf{°}}\mathit{C}$  to ${\mathbf{37}}^{\mathbf{°}}\mathit{C}$ ?

Calculate each of the following quantities: (a) Volume of 2.050 M copper(II) nitrate that must be diluted with water to prepare 750.0 mL of a 0.8543 M solution (b) Volume of 1.63 M calcium chloride that must be diluted with water to prepare 350. mL of a 2.86102 M chloride ion solution (c) Final volume of a 0.0700 M solution prepared by diluting 18.0 mL of 0.155 M lithium carbonate with water.

Draw orbital-energy splitting diagrams and use the spectrochemical series to show the orbital occupancy for each of the following (assuming that  is a weak-field ligand):

(a) ${\left[\mathrm{Fe}{\left(C_2{O}_4\right)}_3\right]}^{\mathbf{3}\mathbf{-}}$ (${\mathbf{C}}_{\mathbf{2}}{{\mathbf{O}}_{\mathbf{4}}}^{\mathbf{2}\mathbf{-}}$creates a weaker field than ${\mathbf{H}}_{\mathbf{2}}\mathbf{O}$ does.)  (b) ${\left[\mathrm{Co}{\left(\mathrm{CN}\right)}_6\right]}^{\mathbf{4}\mathbf{-}}$ (c) ${\left[{\mathrm{MnCl}}_6\right]}^{\mathbf{4}\mathbf{-}}$

From the following reaction and data, find (a)${\mathit{S}}^{\mathbf{°}}\mathbf{ }\mathit{o}\mathit{f}\mathbf{ }\mathit{S}\mathit{O}\mathit{C}{\mathit{l}}_{\mathbf{2}}$  and (b) T at which the reaction becomes nonspontaneous:

$$\begin{gathered} {\mathbf{\text{SO}}}_{\mathbf{\text{3}}}{\mathbf{\text{(g) + SCl}}}_{\mathbf{\text{2}}}\mathbf{\text{(l }}\mathbf{\to }{\mathbf{\text{SOCl}}}_{\mathbf{\text{2}}}{\mathbf{\text{(l) + SO}}}_{\mathbf{\text{2}}}{\mathbf{\text{(g) ∆G}}}_{\mathbf{r}\mathbf{x}\mathbf{n}}^{\mathbf{°}}\mathbf{\text{= -75.2kJ }} \\ \mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }{\mathbf{\text{SO}}}_{\mathbf{\text{3}}}{\mathbf{\text{(g) SCl}}}_{\mathbf{\text{2}}}{\mathbf{\text{(l) SOCl}}}_{\mathbf{\text{2}}}{\mathbf{\text{(l) SO}}}_{\mathbf{\text{2}}}\mathbf{\text{(g)}} \\ \mathbf{∆}{\mathit{H}}_{\mathbf{f}}^{\mathbf{°}}\left(kJ/mol\right)\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{-}\mathbf{396}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{-}\mathbf{50}\mathbf{.}\mathbf{0}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{-}\mathbf{245}\mathbf{.}\mathbf{6}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{-}\mathbf{296}\mathbf{.}\mathbf{8} \\ {\mathit{S}}^{\mathbf{°}}\left(J/mol\times K\right)\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{256}\mathbf{.}\mathbf{7}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{184}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{-}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{248}\mathbf{.}\mathbf{1}\mathbf{ } \end{gathered}$$

A complex ${\mathbf{ML}}_{\mathbf{6}}^{\mathbf{2}\mathbf{+}}$is violet. The same metal forms a complex with another ligand, Q, that creates a weaker field. What colour ${\mathbf{MQ}}_{\mathbf{6}}^{\mathbf{2}\mathbf{+}}$ might be expected to show? Explain.

 ${\left[\mathrm{Cr}{\left(H_{2}O\right)}_6\right]}^{\mathbf{2}\mathbf{+}}$is violet. Another ${\mathbf{CrL}}_{\mathbf{6}}$ complex is green. Can ligand L be CN? Can it be ${\mathbf{Cl}}^{\mathbf{-}}$? Explain..

A key step in the metabolism of glucose for energy is the isomerization of glucose-6-phosphate (G6P) to fructose-6- phosphate (F6P):  

$\mathbf{\text{G6P}}\mathbf{\rightleftharpoons }\mathit{F}\mathbf{6}\mathit{P}\mathbf{;}\mathbf{ }\mathbf{ }\mathit{K}\mathbf{=}\mathbf{ }\mathbf{0}\mathbf{.}\mathbf{510}\mathbf{ }\mathit{a}\mathit{t}\mathbf{ }\mathbf{298}\mathit{K}$

(a) Calculate $\mathbf{∆}{\mathit{G}}^{\mathbf{°}}$ at $\mathbf{298}\mathit{K}$. 

(b) Calculate $\mathbf{∆}\mathit{G}$ when Q, the [F6P]/[G6P] ratio, equals$\mathbf{10}\mathbf{.}\mathbf{0}$ . 

(c) Calculate $\mathbf{∆}\mathit{G}$ when $\mathit{Q}\mathbf{=}\mathbf{0}\mathbf{.}\mathbf{100}$. 

(d) Calculate Q if$\mathbf{ }\mathit{G}\mathbf{ }\mathbf{=}\mathbf{ }\mathbf{ }\mathbf{-}\mathbf{ }\mathbf{2}\mathbf{.}\mathbf{50}\mathit{k}\mathit{J}\mathbf{/}\mathit{m}\mathit{o}\mathit{l}$ .

The hexaaqua complex ${\left[\mathrm{Ni}{\left(H_{2}O\right)}_6\right]}^{\mathbf{2}\mathbf{+}}$ is green, whereas the hexaammonia complex ${\mathbf{\left[}\mathbf{Ni}{\left({\mathrm{NH}}_3\right)}_{\mathbf{6}}\mathbf{\right]}}^{\mathbf{2}\mathbf{+}}$ is violet. Explain

Three of the complex ions that are formed by ${\mathbf{Co}}^{\mathbf{3}\mathbf{+}}$ are ${\mathbf{\left[}\mathbf{Co}{\left(H_{2}O\right)}_{\mathbf{6}}\mathbf{\right]}}^{\mathbf{3}\mathbf{+}}\mathbf{,}{\mathbf{\left[}\mathbf{Co}{\left({\mathrm{NH}}_3\right)}_{\mathbf{6}}\mathbf{\right]}}^{\mathbf{3}\mathbf{+}}\mathbf{,}\mathbf{ }\mathbf{and}\mathbf{ }{\mathbf{\left[}{\mathbf{CoF}}_{\mathbf{6}}\mathbf{\right]}}^{\mathbf{3}\mathbf{-}}$. These ions have the observed colours (listed in arbitrary order) yellow-orange, green, and blue. Match each complex with its colour. Explain.

When neptunium (Np) and plutonium (Pu) were discovered, the periodic table did not include the actinides, so these elements were placed in Group 7B(7) and 8B(8). When americium (Am) and curium (Cm) were synthesized, they were placed in Group 8B(9) and 8B(10). However, during chemical isolation procedures, Glenn Seaborg and his group, who had synthesized these elements, could not find their compounds among other compounds of these groups, which led Seaborg to suggest they were part of a new inner transition series. 

(a) How do the electron configurations of these elements support Seaborg’s suggestion?

(b) The highest fluorides of Np and Pu are hexafluorides, as is the highest fluoride of uranium. How does this chemical evidence support the placement of Np and Pu as inner transition elements rather than transition elements?

How many different formulas are there for octahedral complexes with a metal M and four ligands A, B, C, and D? Give the number of isomers for each formula and describe the isomers.

The mole is defined in terms of the carbon-12 atom. Use the definition to find (a) the mass in grams equal to 1 atomic mass unit; (b) the ratio of the gram to the atomic mass unit.

Brass, an alloy of copper and zinc, can be produced by simultaneously electroplating the two metals from a solution containing their $\mathbf{2}\mathbf{+}$ ions. If $\mathbf{65}\mathbf{.}\mathbf{0}\mathbf{\%}$ of the total current is used to plate copper, while $\mathbf{35}\mathbf{.}\mathbf{0}\mathbf{\%}$ goes to plating zinc, what is the mass percent of copper in the brass?

Serotonin ( µ=176 g/mol) transmits nerve impulses between neurons. It contains 68.2 mass % C, 6.86 mass % H, 15.9 mass % N, and 9.08 mass % O. What is its molecular formula?

Disulfur decafluoride is intermediate in reactivity between ${\mathbf{SF}}_{\mathbf{4}}$ and ${\mathbf{SF}}_{\mathbf{6}}$. It disproportionates at 150 C to these monosulfur fluorides. Write a balanced equation for this reaction, and give the oxidation state of S in each compound.

In 1940, when the elements Np and Pu were prepared, a controversy arose about whether the elements from Ac on were analogs of the transition elements (and related to Y through Mo) or analogs of the lanthanides (and related to La through Nd). The arguments hinged primarily on comparing observed oxidation states to those of the earlier elements. 

(a) If the actinides were analogs of the transition elements, what would you predict about the maximum oxidation state for U? For Np? 

(b) If the actinides were analogs of the lanthanides, what would you predict about the maximum oxidation state for U? For Pu?

In many species, a transition metal has an unusually high or low oxidation state. Write balanced equations for the following and find the oxidation state of the transition metal in the product: 

(a) Iron (III) ion reacts with hypochlorite ion in basic solution to form ferrate ion $\mathbf{\left(}{\mathbf{FeO}}_{\mathbf{4}}^{\mathbf{2}\mathbf{-}}\mathbf{\right)}\mathbf{,}\mathbf{ }{\mathbf{Cl}}^{\mathbf{-}}$and water.

(b) Potassium hexacyanomanganate(II) reacts with the K metal to form ${\mathbf{K}}_{\mathbf{6}}\mathbf{\left[}\mathbf{Mn}{\mathbf{\left(}\mathbf{CN}\mathbf{\right)}}_{\mathbf{6}}\mathbf{\right]}$.

(c) Heating sodium superoxide $\left({\mathrm{NaO}}_2\right)$ with ${\mathbf{Co}}_{\mathbf{3}}{\mathbf{O}}_{\mathbf{4}}$produces ${\mathbf{Na}}_{\mathbf{4}}{\mathbf{CoO}}_{\mathbf{4}}$ and ${\mathbf{O}}_{\mathbf{2}}$ gas.

(d) Vanadium(III) chloride reacts with Na metal under a CO atmosphere to produce $\mathbf{Na}\left[V{\left(\mathrm{CO}\right)}_6\right]$ and NaCl.

(e) Barium peroxide reacts with nickel(II) ions in a basic solution to produce ${\mathbf{BaNiO}}_{\mathbf{3}}$

(f) Bubbling CO through a basic solution of cobalt(II) ion produces ${\left[\mathrm{Co}{\left(\mathrm{CO}\right)}_4\right]}^{-}\mathbf{,}\mathbf{ }{{\mathbf{CO}}_{\mathbf{3}}}^{\mathbf{2}\mathbf{-}}$and water.

(g) Heating caesium tetrafluorocuprate(II) with ${\mathbf{F}}_{\mathbf{2}}$ gas under pressure gives ${\mathbf{Cs}}_{\mathbf{2}}{\mathbf{CuFe}}_{\mathbf{6}}$.

(h) Heating tantalum(V) chloride with Na metal produces NaCl and ${\mathbf{Ta}}_{\mathbf{6}}{\mathbf{Cl}}_{\mathbf{15}}$, in which half of the Ta is in the +2 state.

(i) Potassium tetracyanonickelate(II) reacts with hydrazine $\left(N_2{H}_4\right)$ in basic solution to form ${\mathbf{K}}_{\mathbf{4}}\left[{\mathrm{Ni}}_2{\left(\mathrm{CN}\right)}_6\right]$ and ${\mathbf{N}}_{\mathbf{2}}$ gas.

Draw a Lewis structure with lowest formal charges for  ${\text{MnO}}_4$

Which separation method is operating in each of the following procedures: (a) pouring a mixture of cooked pasta and boiling water into a colander; (b) removing colored impurities from raw sugar to make refined sugar; (c) preparing coffee by pouring hot water through ground coffee beans?

Commercial aluminium production is done by the electrolysis of a bath containing ${\mathbf{\text{Al}}}_{\mathbf{\text{2}}}{\mathbf{\text{O}}}_{\mathbf{\text{3}}}$ dissolved in molten ${\mathbf{\text{Na}}}_{\mathbf{\text{3}}}{\mathbf{\text{AlF}}}_{\mathbf{\text{6}}}$. Why isn’t it done by electrolysis of an aqueous AlCl₃ solution?

In the sepia "loning" of a black-and-white photograph, the image is converted to a rich brownish violet by placing the finished photograph in a solution of gold (III) ions, in which metallic gold replaces the metallic silver. Use Appendix D to explain the chemistry of this process.

An octahedral complex with three different ligands can have formulas with three different ratios of the ligands: 

${\left[{\text{MA}}_4\text{BC}\right]}^{4+}$, such as ${\left[\text{Co}{\left({\text{NH}}_3\right)}_4\left({\text{H}}_2\text{O}\right)\text{Cl}\right)}^{2+}$

$\left[{\text{MA}}_3{\text{B}}_2{\text{C}}^{2+}\right.$, such $\left[\text{Cr}{({\text{H}}_2\text{O}⟩}_3{\text{Br}}_2\text{Cl}\right]$

${\left[{\text{MA}}_2{\text{B}}_2{\text{C}}_2\right]}^{*+}$, such as $\left[\text{Cr}{\left({\text{NH}}_3\right)}_2{\left({\text{H}}_2{\text{O}}_2{\text{Br}}_2\right]}^{+}\right.$

In black-and-white photography, what are the major chemical changes involved in exposing, developing, and fixing?

 In  $\left[Cr{\left(N{H}_3\right)}_6\right]\mathit{C}{\mathit{l}}_{\mathbf{3}}$ , the ${\left[Cr{\left(N{H}_3\right)}_6\right]}^{\mathbf{3}\mathbf{+}}$ ion absorbs visible light in the blue-violet range, and the compound is yellow-orange. In $\left[Cr{\left(H_{2}O\right)}_6\right]\mathit{B}{\mathit{r}}_{\mathbf{3}}$  , the ${\left[Cr{\left(H_{2}O\right)}_6\right]}^{\mathbf{3}\mathbf{+}}$ ion absorbs visible light in the red range, and the compound is blue-gray. Explain these differences in light absorbed and color of the compound.

Dark green manganate salts contain the  $Mn{O_4}^{2-}$ ion. The ion is stable in basic solution but disproportionates in acid to $Mn{O}_2\left(s\right)$  and $Mn{O_4}^{-}$.

(a) What is the oxidation state of$Mn$in $Mn{O_4}^{-}$, and  $Mn{O}_2$? 

(b) Write a balanced equation for the reaction of   in acidic solution.1

Dark green manganate salts contain the  $\mathit{M}\mathit{n}{{\mathbf{O}}_{\mathbf{4}}}^{\mathbf{2}\mathbf{-}}$ ion. The ion is stable in basic solution but disproportionates in acid to $\mathit{M}\mathit{n}{\mathit{O}}_{\mathbf{2}}\mathbf{\left(}\mathit{s}\mathbf{\right)}$  and $\mathit{M}\mathit{n}{{\mathbf{O}}_{\mathbf{4}}}^{\mathbf{-}}$  . 

(a) What is the oxidation state of $Mn$  in  $\mathit{M}\mathit{n}{{\mathbf{O}}_{\mathbf{4}}}^{\mathbf{2}\mathbf{-}}$,   $\mathit{M}\mathit{n}{{\mathbf{O}}_{\mathbf{4}}}^{\mathbf{-}}$ , and  $\mathit{M}\mathit{n}{\mathit{O}}_{\mathbf{2}}$?

(b) Write a balanced equation for the reaction of $\mathit{M}\mathit{n}{{\mathbf{O}}_{\mathbf{4}}}^{\mathbf{2}\mathbf{-}}$  in acidic solution.1

Aqueous electrolysis of potassium manganate $K_{2}Mn{O}_4$ in basic solution is used for the production of tens of thousands of tons of potassium permanganate $KMn{O}_4$ annually. 

(a) Write a balanced equation for the electrolysis reaction. (Water is reduced also.)

(b) How many moles of $Mn{O}_4$ can be formed if $12$ A flows through a tank of aqueous $Mn{O_4}^{2-}$  for $96$ h? $1$

Consider the square planar complex shown at right. Which of the structures below are geometric isomers of it?  

Several coordination isomers, with both Co and Cr as$3 +$ ions, have the molecular formula ${\text{CoCrC}}_6{\text{H}}_{18}{\text{N}}_{12}$

(a) Give the name and formula of the isomer in which the Co complex ion has six  ${\text{NH}}_3$ groups. 

(b) Give the name and formula of the isomer in which the Co complex ion has one $CN$ and five $N{H}_3$ groups.

Several coordination isomers have the molecular formula${\text{Pt}}_2{\text{H}}_{12}{\text{Cl}}_6{\text{N}}_4$ . 

(a) Give the name and standard formula of the isomer in which the $Pt$ complex ion has six $\text{Cl}$ groups and a charge of $2-$ . 

(b) Give the name and standard formula of the isomer in which the $2 -$Pt complex ion has four  groups and a charge of 

A shortcut to finding optical isomers is to see if the complex has a plane of symmetry-a plane passing through the metalatom such that every atom on one side of the plane is matched by an identical one at the same distance from the plane on the other side. Any planar complex has a plane of symmetry since all atoms lie in one plane. Use this approach to determine whether these exist as optical isomers: 

(a)$\left[\text{Zn}{\left({\text{NH}}_3\right)}_2{\text{Cl}}_2\right]$  (tetrahedral);

(b) ${\left[\text{Pt}{\left(\text{en}\right)}_2\right]}^{\mathbf{2}\mathbf{+}}\mathbf{;}$  

(c)  trans-${\mathbf{\left[}{\mathbf{\text{PtBr}}}_{\mathbf{4}}{\mathbf{\text{Cl}}}_{\mathbf{2}}\mathbf{\right]}}^{\mathbf{2}\mathbf{-}}$ ; 

(d) $\mathit{t}\mathit{r}\mathit{a}\mathit{n}\mathit{s}\mathbf{-}\mathbf{[}\mathbf{C}\mathbf{o}\mathbf{(}\mathbf{e}\mathbf{n}{\mathbf{)}}_{\mathbf{2}}{\mathbf{F}}_{\mathbf{2}}{\mathbf{]}}^{\mathbf{+}}$

(e) cis- .${\left[\text{Co}{\left(\text{en}\right)}_2{\text{F}}_2\right]}^{+}$

Some octahedral complexes have dissented shapes. In some, two metal-ligand bonds that are  apart are shorter than the other four. In , for example, two  bonds are  long, and the other four are  long. 

(a) Calculate the longest distance between two  atoms in this complex. 

(b) Calculate the shortest distance between two  atoms.

A chemist makes four successive  dilutions of $\mathbf{1}\mathbf{.}\mathbf{0}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{5}}\mathbf{ }\mathbf{MHCl}$ . Calculate the pH of the original solution and of each diluted solution (through) $\mathbf{1}\mathbf{.}\mathbf{0}\mathbf{\times }{\mathbf{10}}^{\mathbf{-}\mathbf{9}}\mathbf{ }\mathbf{MHCl}$.

Chlorobenzene, ${\mathbf{\text{C}}}_{\mathbf{\text{6}}}{\mathbf{\text{H}}}_{\mathbf{\text{5}}}\mathbf{\text{Cl}}$, is a key intermediate in the manufacture of dyes and pesticides. It is made by the chlorination of benzene, catalyzed by ${\mathbf{\text{FeCl}}}_{\mathbf{\text{3}}}$, in this series of steps: 

 (1) $\mathbf{ }{\mathbf{\text{Cl}}}_{\mathbf{\text{2}}}{\mathbf{\text{ + FeCl}}}_{\mathbf{\text{3}}}\mathbf{\rightleftharpoons }{\mathbf{\text{FeCl}}}_{\mathbf{\text{5}}}{\mathbf{\text{(orCl}}}^{\mathbf{\text{ + }}}\mathbf{\text{FeC}}{{\mathbf{\text{l}}}_{\mathbf{\text{4}}}}^{\mathbf{\text{ - }}}\mathbf{\text{)}}$

 (2) ${\mathbf{\text{C}}}_{\mathbf{\text{6}}}{\mathbf{\text{H}}}_{\mathbf{\text{6}}}{\mathbf{\text{ + Cl}}}^{\mathbf{\text{ + }}}{\mathbf{\text{FeCl}}}_{\mathbf{\text{4}}}^{\mathbf{\text{ - }}}\mathbf{\rightleftharpoons }{\mathbf{\text{C}}}_{\mathbf{\text{6}}}{\mathbf{\text{H}}}_{\mathbf{\text{6}}}{\mathbf{\text{Cl}}}^{\mathbf{\text{ + }}}{\mathbf{\text{ + FeCl}}}_{\mathbf{\text{4}}}^{\mathbf{\text{ - }}}$

 (3) ${\mathbf{\text{C}}}_{\mathbf{\text{6}}}{\mathbf{\text{H}}}_{\mathbf{\text{6}}}{\mathbf{\text{Cl}}}^{\mathbf{\text{ + }}}\mathbf{\rightleftharpoons }{\mathbf{\text{C}}}_{\mathbf{\text{6}}}{\mathbf{\text{H}}}_{\mathbf{\text{5}}}{\mathbf{\text{Cl + H}}}^{\mathbf{\text{ + }}}$

 (4) ${\mathbf{\text{H}}}^{\mathbf{\text{ + }}}{\mathbf{\text{ + FeCl}}}_{\mathbf{\text{4}}}^{\mathbf{\text{ - }}}\mathbf{\rightleftharpoons }{\mathbf{\text{HCl + FeCl}}}_{\mathbf{\text{3}}}$

(a) Which of the step(s) is (are) Lewis acid-base reactions?

 (b) Identify the Lewis acids and bases in each of those steps.

Hydrogen peroxide, ${\mathbf{\text{H}}}_{\mathbf{\text{2}}}{\mathbf{\text{O}}}_{\mathbf{\text{2}}}$ (${\mathbf{\text{pK}}}_{\mathbf{\text{a}}}\mathbf{\text{ = 11.75}}$), is a bleaching agent and antiseptic. It is sold as 3% ${\mathbf{\text{H}}}_{\mathbf{\text{2}}}{\mathbf{\text{O}}}_{\mathbf{\text{2}}}$ by mass and contains  0.001% ${\mathbf{\text{H}}}_{\mathbf{\text{3}}}{\mathbf{\text{PO}}}_{\mathbf{\text{4}}}$ by mass to stabilize the solution. Which contributes more ${\mathbf{\text{H}}}_{\mathbf{\text{3}}}{\mathbf{\text{O}}}^{\mathbf{\text{ + }}}$  to the solution, the ${\mathbf{\text{H}}}_{\mathbf{\text{2}}}{\mathbf{\text{O}}}_{\mathbf{\text{2}}}$ or the  ${\mathbf{\text{H}}}_{\mathbf{\text{3}}}{\mathbf{\text{PO}}}_{\mathbf{\text{4}}}$?

7 Esters, RCOOR’, are formed by the reaction of carboxylic acids, RCOOH, and alcohols, R’OH, where R and R’ are hydrocarbon groups. Many esters are responsible for the odors of fruit and, thus, have important uses in the food and cosmetics industries. The first two steps in the mechanism of ester formation are

Identify the Lewis acids and Lewis bases in these two steps.

Liquid ammonia auto ionizes like water:

${\mathbf{\text{2NH}}}_{\mathbf{\text{3}}}\mathbf{\text{(l)}}\mathbf{\to }{\mathbf{\text{NH}}}_{\mathbf{\text{4}}}^{\mathbf{\text{ + }}}{\mathbf{\text{(am) + NH}}}_{\mathbf{\text{2}}}^{\mathbf{\text{ - }}}\mathbf{\text{(am)}}$

where (am) represents solvation by ${\mathbf{\text{NH}}}_{\mathbf{\text{3}}}$. 

(a) Write the ion-product constant expression, Kam.

b) What are the strongest acid and base that can exist in ${\mathbf{\text{NH}}}_{\mathbf{\text{3}}}$ (l)? 

(c) ${\mathbf{\text{HNO}}}_{\mathbf{\text{3}}}$  and HCOOH are levelled in ${\mathbf{\text{NH}}}_{\mathbf{\text{3}}}$  (l). Explain with equations. 

(d) At the boiling point($\mathbf{-}\mathbf{33}\mathbf{°}\mathbf{C}$), ${\mathbf{\text{K}}}_{\mathbf{\text{am }}}{\mathbf{\text{ = 5.1×10}}}^{\mathbf{-}\mathbf{27}}$. Calculate [$\mathbf{\text{N}}{{\mathbf{\text{H}}}_{\mathbf{\text{4}}}}^{\mathbf{\text{ + }}}$] at this temperature. 

(e) Pure sulfuric acid also auto ionizes. Write the ion-product constant expression, ${\mathbf{\text{K}}}_{\mathbf{\text{sulf }}}$ , and find the concentration of the conjugate base at $\mathbf{20}\mathbf{°}\mathbf{C}$$\left({\text{K}}_{\text{sutf }}{\text{ = 2.7×10}}^{-4}\text{at 20°C}\right)$

Thiamine hydrochloride $\left({\text{C}}_{\text{12}}{\text{H}}_{\text{18}}{\text{ON}}_{\text{4}}{\text{SCl}}_{\text{2}}\right)$ is a water soluble form of thiamine (vitamin B1; ${\mathbf{\text{K}}}_{\mathbf{\text{a}}}\mathbf{\text{ = 3.37}}\mathbf{\times }{\mathbf{\text{10}}}^{\mathbf{\text{ - 7}}}$. How many grams of the hydrochloride must be dissolved in 10.00 mL of water to give a pH of 3.50?

At $\mathbf{50}\mathbf{°}\mathbf{C}$ and 1 atm, ${\mathbf{\text{K}}}_{\mathbf{\text{w}}}\mathbf{\text{ = 5.19}}\mathbf{\times }{\mathbf{\text{10}}}^{\mathbf{\text{ - 14}}}$. At these conditions, find

 (a)$\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{ + }}\right]$  in pure water, 

(b)  $\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{ + }}\right]$ in 0.010 MNaOH , and

(c) [OH] in ${\mathbf{\text{0.0010MHClO}}}_{\mathbf{\text{4}}}$. 

(d) Find $\left[{\text{H}}_{\text{3}}{\text{O}}^{\text{ + }}\right]$ in 0.0100 MKOH at $\mathbf{100}\mathbf{°}\mathbf{C}$ and 1000  atm (Kw = 1.101012). 

(e) Find the pH of pure water at $\mathbf{100}\mathbf{°}\mathbf{C}$and 1000 atm

The Group 5A(15) hydrides react with boron trihalides in a reversible Lewis acid-base reaction. When 0.15 mol of ${\mathbf{\text{PH}}}_{\mathbf{\text{3}}}{\mathbf{\text{BCl}}}_{\mathbf{\text{3}}}$  (s) is introduced into a  3.0 -Container at a certain temperature, $\mathbf{\text{8.4}}\mathbf{\times }{\mathbf{\text{10}}}^{\mathbf{\text{ - 3}}}$ mol of  ${\mathbf{\text{PH}}}_{\mathbf{\text{3}}}$ is present at equilibrium: 

${\mathbf{\text{PH}}}_{\mathbf{\text{3}}}{\mathbf{\text{BCl}}}_{\mathbf{\text{3}}}\mathbf{\text{(s)}}\mathbf{\rightleftharpoons }{\mathbf{\text{PH}}}_{\mathbf{\text{3}}}{\mathbf{\text{(g) + BCl}}}_{\mathbf{\text{3}}}\mathbf{\text{(g)}}$

(a) Find ${\text{K}}_{\text{c}}$for the reaction at this temperature. 

(b) Draw a Lewis structure for the reactant