Chapter 1: Chemists and Chemistry

An electron is trapped in an octahedral hole in a closest packed array of aluminum atoms (assume they behave as uniform hard spheres). In this situation, the energy of the electron is quantized and the lowest-energy transition corresponds to a wavelength of 9.50nm . Assuming that the hole can be approximated as a cube, what is the radius of a sphere that will just fit in the octahedral hole? Reference Exercise 164 in Chapter 12 for the energy equation for a particle in a cube.

Question:14. Suppose$10.00g$of an alkaline earth metal reacts with$10.0L$of water to produce$6.10L$of hydrogen gas at $1.00atm$and$25C$.Identify the metal and determine$pH$ of the solution.

The structures of another class of high-temperature ceramic superconductors are shown below.

(a) Determine the formula of each of these four superconductors.

(b) One of the structural features that appears to be essential for high-temperature superconductivity is the presence of planar sheets of copper and oxygen atoms. As the number of sheets in each unit cell increases, the temperature for the onset of superconductivity increases. Order the four structures from the lowest to highest superconducting temperature.

(c) Assign oxidation states to Cu in each structure assuming that Tl exists as T1³⁺. The oxidation states of Ca, Ba, and O are assumed to be +2, +2, and -2, respectively.

(d) It also appears that copper must display a mixture of oxidation states for a material to exhibit superconductivity. Explain how this occurs in these materials as well as in the superconductor in Exercise 79.

How would transition metal ions be classified using the Lewis definition of acids and bases? What must a ligand have to bond to a metal? What do we mean when we say that a bond is a “coordinate covalent bond”?

The compound cisplatin, $\mathbf{Pt}{\left({\mathrm{NH}}_3\right)}_{\mathbf{2}}{\mathbf{Cl}}_{\mathbf{2}}$, has been studied extensively as an antitumor agent. The reaction for the synthesis of cisplatin is:

${\mathbf{K}}_{\mathbf{2}}{\mathbf{PtCl}}_{\mathbf{4}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{+}\mathbf{2}{\mathbf{NH}}_{\mathbf{3}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{\to }\mathbf{Pt}\mathbf{(}{\mathbf{NH}}_{\mathbf{3}}{\mathbf{)}}_{\mathbf{2}}{\mathbf{Cl}}_{\mathbf{2}}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{+}\mathbf{2}\mathbf{KCl}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}$

Write the electron configuration for platinum ion in cisplatin. Most d8 transition metal ions exhibit square planar geometry. With this and the name in mind, draw the structure of cisplatin.

What is the electron configuration for the transition metal ion(s) in each of the following compounds?

Pt forms +2 and +4 oxidation states in compounds.

Question: An element X has five major isotopes, which are listed below along with their abundances. Calculate the average atomic mass, and identify the element.

The reaction $\mathbf{2}\mathbf{NO}\mathbf{\left(}\mathbf{g}\mathbf{\right)}\mathbf{+}{\mathbf{O}}_{\mathbf{2}}\stackrel{}{\mathbf{\to }}\mathbf{2}{\mathbf{NO}}_{\mathbf{2}}\mathbf{\left(}\mathbf{g}\mathbf{\right)}$was studied, and the following data were obtained,

Where,$\mathbf{Rate}\mathbf{=}\mathbf{-}\frac{\mathbf{d}\left[O_2\right]}{\mathbf{dt}}$.

What would be the initial rate for an experiment where

${\left[\mathrm{NO}\right]}_{\mathbf{0}}\mathbf{=}\mathbf{6}\mathbf{.}\mathbf{21}\mathbf{x}{\mathbf{10}}^{\mathbf{18}}\mathbf{molecules}\mathbf{/}{\mathbf{cm}}^{\mathbf{3}}\mathbf{and}{\left[O_2\right]}_{\mathbf{0}}\mathbf{=}\mathbf{7}\mathbf{.}\mathbf{35}\mathbf{x}{\mathbf{10}}^{\mathbf{18}}\mathbf{molecules}\mathbf{/}{\mathbf{cm}}^{\mathbf{3}}$ ?

an object of mass m (in grams) attached to a coiled spring with damping factor b (in grams per second) is pulled down a distance a (in centimeters) from its rest position and then released. Assume that the positive direction of the motion is up and the period is T (in seconds) under simple harmonic motion.

(a) Develop a model that relates the distance d of the object from its rest position after t seconds.

(b) Graph the equation found in part (a) for 5 oscillations using a graphing utility.

Given values: m = 10, a = 5, b = 0.8, T = 3

The reaction ${\mathbf{H}}_{\mathbf{2}}{\mathbf{SeO}}_{\mathbf{3}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{+}\mathbf{6}{\mathbf{I}}^{\mathbf{-}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{+}\mathbf{4}{\mathbf{H}}^{\mathbf{+}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{\to }\mathbf{Se}\mathbf{\left(}\mathbf{s}\mathbf{\right)}\mathbf{+}\mathbf{2}{{\mathbf{I}}_{\mathbf{3}}}^{\mathbf{-}}\mathbf{\left(}\mathbf{aq}\mathbf{\right)}\mathbf{+}\mathbf{3}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}\mathbf{\left(}\mathbf{l}\mathbf{\right)}$was studied at ${\mathbf{0}}^{\mathbf{°}}\mathbf{C}$, and the following data were obtained:

The relationships hold only if there is an insignificant amount of ${{\mathbf{I}}_{\mathbf{3}}}^{\mathbf{-}}$ present. What is the rate law and the value of the rate constant?

$\left(\mathrm{Assume}\mathrm{that}\mathrm{rate}=-\frac{d\left[H_2{\mathrm{SeO}}_3\right]}{\mathrm{dt}}.\right)$