CHEMISTRY COMMUNITY

Kyleigh Follis 2H

For the anode (left half of the cell diagram), oxygen is oxidized. So H20 -> H+ + e- + O2. For the cathode (right half of the cell diagram), oxygen is reduced. So 02 + e- -> OH-.+ H20.

Kyleigh Follis 2H

The unique reaction rate is equal to -1/a of the reaction rate of O2. So, given the unique reaction rate = 0.44, then 0.44 = -1/3 (rate of O2). So you would multiply both sides by 3, which gives you 1.3 for the rate of O2.

Kyleigh Follis 2H

The equilibrium constant includes both gases and aqueous species.

Kyleigh Follis 2H

This is refereeing to delta S surrounding is equal to negative delta H divided by temperature.

Kyleigh Follis 2H

There were a few homework problems about this topic, so it could be tested on.

Kyleigh Follis 2H

When determining the rate of a reaction, the concentration of the reactants is raised to the power of the reaction order.

Kyleigh Follis 2H

B forms twice as fast as A is depleted. For 0.19M of B to form, 1/2 of that is lost form A. So the concentration of A is 0.15M - 1/2(0.19M).

Kyleigh Follis 2H

In a regular calorimeter, the reaction takes place in the water. In a bomb calorimeter, the reaction takes place in a sealed metal container.

Kyleigh Follis 2H

Kyleigh Follis 2H

Due to the Nernst equation, Ecell > 0 when Q is < 0, so the concentration of the cathode will be greater than the concentration of the anode because Q = concentration of left (anode) divided by concentration of right (cathode).

Kyleigh Follis 2H

The reaction rate is the change in concentration of one of the reactants or products at a selected stage of the reaction divided by the time interval over which the change takes place. The unique average rate of the reaction is the average rate divided by the stoichiometric coefficients, so the uniq...

Kyleigh Follis 2H

C is oxidized because its oxidation state in C2H5OH is -2 and its oxidation state in C2H4) is -1. So its oxidation number decreases which means it was oxidized because it lost 1 electron.

Kyleigh Follis 2H

For problem 6.57 in the 7th edition, why is the value of Ka for HF the square root of K?

Kyleigh Follis 2H

It means that Cu+ is a stronger oxidizing agent than H+.

Kyleigh Follis 2H

For outline 4, it covers 6K, 6L, and 6M.

Kyleigh Follis 2H

Yes, this is correct.

Kyleigh Follis 2H

Does a galvanic cell always have a positive potential difference?

Kyleigh Follis 2H

Pt is included because in the cathode are two ion compounds in solution, so an inert electrode is needed.

Kyleigh Follis 2H

Which topic sections will be covered on Test 2 in Focus 6?

Kyleigh Follis 2H

How does one calculate Delta S of fusion, as in the example provided in the 7th edition 4J.1?

Kyleigh Follis 2H

The change in internal energy equals 0 when it is an isothermal process.

Kyleigh Follis 2H

no, no calculus will be required on the exam.

Kyleigh Follis 2H

What does it mean if the transfer of heat is reversible?

Kyleigh Follis 2H

Why can the change in entropy that has been calculated for a reversible path be used to calculate the change in entropy of the gas when it expands irreversibly?

Kyleigh Follis 2H

What is the difference in units between the standard enthalpy and the enthalpy of formation?

Kyleigh Follis 2H

Why does steam at 100 degrees celsius cause a worse burn than boiling water at 100 degrees celsius?

Kyleigh Follis 2H

When converting between celsius and kelvin, what are the significant figure rules?

Kyleigh Follis 2H

What is the difference between a closed, an open, and an isolated system? And what are some examples?

Kyleigh Follis 2H

Why does a change in pressure due to an inert gas not affect the equilibrium?

Kyleigh Follis 2H

Why does an increase in temperature with an endothermic reaction favor the formation of products? Conversely, why does an increase in temperature with an exothermic reaction favor the formation of reactants?

Kyleigh Follis 2H

I also calculated it to be 4.84.

Kyleigh Follis 2H

A change in one of the variables that describe a system at equilibrium produces a shift in the position of the equilibrium that counteracts the effect of this change. Le Chatelier's principle describes what happens to a system when something momentarily takes it away from equilibrium. This can be us...

Kyleigh Follis 2H

Why does K remain constant when there is a change in pressure, but K changes when there is a change in temperature.

Kyleigh Follis 2H

Why are solids and liquids not included in the K expression?

Kyleigh Follis 2H

Molecules with a dipole moment (polar molecules) dissolve in polar liquids like water.

Kyleigh Follis 2H

ClF3 has a net dipole because the shape of the molecule is T-shape and the dipoles do not cancel each other out. BF3 does not have a net dipole because the shape is trigonal planar and the dipoles cancel each other out.

Kyleigh Follis 2H

Cl- < S-2 < P-3 < I- Large anions will be the most polarizable because the outer electrons are held more loosely and can be more easily distorted by the cation. Cs+ < Ba+2 < Ca+2 < Li+ Small cations will have the most polarizing power because they distort the electron cloud of the anion better due t...

Kyleigh Follis 2H

An induced dipole intermolecular force results from the presence of molecules that are permanent dipoles temporarily distorting the electron charge in other nearby polar or nonpolar molecules, thereby inducing further polarization. Van der Waals forces are temporary charges on an atom because of the...

Kyleigh Follis 2H

The number of hybrid orbitals equals the number of atomic orbitals mixed. The number of hybrid orbitals is equal to the steric number which the number of sigma bonds plus number of lone pairs of electrons around the atom.

Kyleigh Follis 2H

A ligand is a molecule or ion that bonds with a metal atom. What we're focusing on is ligands bonding to central transition metals to form coordination compounds. The transition metal itself is typically not the ligand.

Kyleigh Follis 2H

This is no ordinary triple bond as the second π interaction results from a weak interaction of sp2 hybrid orbitals lying in the plane of the ring.
The triple bond is non-linear due to the constraints of the 6-membered ring. Benzyne is strained and highly reactive.

Kyleigh Follis 2H

Dipole-dipole forces result from the difference between electronegativities of the atoms in molecules. It is large enough that the electrons aren't shared equally, and yet small enough that the electrons aren't drawn exclusively to one of the atoms to form positive and negative ions. The bonds in th...

Kyleigh Follis 2H

A sigma bond ( σ bond) is a bond formed by the overlap of orbitals in an end-to-end fashion, with the electron density concentrated between the nuclei of the bonding atoms. A pi bond ( π bond) is a bond formed by the overlap of orbitals in a side-by-side fashion with the electron density concentrate...

Kyleigh Follis 2H

Not sure if you mean NF3, but if so it is because the dipoles do not cancel each other due to the lone pair giving the shape of trigonal pyramidal. So, the N-F polar bonds make the whole molecule polar.

Kyleigh Follis 2H

Three orbitals are arranged around the equator of the molecule with bond angles of 120 degrees. Two orbitals are arranged along the vertical axis at 90 degrees from the equatorial orbitals. The shape of the orbitals is trigonal bipyramidal. Two of the equatorial orbitals contain lone pairs of electr...

Kyleigh Follis 2H

Bond angles will deviate from their ideal values according to the rule that lone pairs repel other electrons more strongly than bonding pairs. Although lone pairs are clearly smaller than atoms, they need to be closer to the nucleus of an atom than a bonding pair. Being closer to the central atom ca...

Kyleigh Follis 2H

A molecule will be trigonal planar if it has 3 pairs of bonding electrons around the central atom. It will be trigonal pyramid if it has 3 bonding pairs of electrons and 1 lone pair of electrons around the central atom. It will be T-shape if it has 3 bonding pairs of electrons and 2 lone pairs of el...

Kyleigh Follis 2H

The seesaw, tetrahedral, and square planar models differ in their number of lone pair of electrons. The tetrahedral model has 4 bonding pairs of electrons around the central atom, the seesaw has 4 bonding pairs and 1 lone pair of electrons around the central atom, and the square planar model has 4 b...

Kyleigh Follis 2H

Because of the constant motion of the electrons, an atom or molecule can develop a temporary (instantaneous) dipole when its electrons are distributed unsymmetrically about the nucleus. A second atom or molecule, in turn, can be distorted by the appearance of the dipole in the first atom or molecule...

Kyleigh Follis 2H

Ammonium chloride is a molecule joined by an ionic bond, so for the lewis structure it is represented by its respective ions NH4+ and Cl-.

Kyleigh Follis 2H

The Ms quantum number is important because 2 electrons in the same orbital cannot have the same the spin. They must have opposite spins. This is known as the Pauli Exclusion Principle. This allows for electrons in the same orbital to have different quantum numbers.

Kyleigh Follis 2H

If the electronegativity difference between atoms is greater than 2, then the atoms will form an ionic bond. If the electronegativity difference between atoms is less than 1.5, then the atoms will form a covalent bond.

Kyleigh Follis 2H

Ms is the spin quantum number. An electron will always be either spin up or spin down. Ms will either be +1/2 or -1/2. You can choose if you want the electron to have the quantum number +1/2 or -1/2. Due to Hund's Rule, electrons in the same subshell occupy different orbitals with parallel spin. If ...

Kyleigh Follis 2H

Yes, every atom can have potentially 8 valence electrons besides H and He.

Kyleigh Follis 2H

The electron structure for Chromium and Copper are examples of elements with incomplete orbitals. For Chromium there is an unfilled 4s orbital with only 1 electron in it, and it has a half filled 3d orbital. For Copper there is an unfilled 4s orbital with only 1 electron in it, and it has a full 3d ...

Kyleigh Follis 2H

First you have to calculate the energy from the lamp, which is simply 32J/s *2s = 64J (1 W = 1 J/s). Next you are given the wavelength of the light that the lamp emits. You can calculate the energy corresponding to that wavelength (using E=hc/wavelength), which would give the the energy PER PHOTON o...

Kyleigh Follis 2H

For the Lyman series,which corresponds to UV light, the electrons come to rest at the energy level n=1.
For the Balmer series, which corresponds to visible light, the electrons come to rest at the energy level n=2.

Kyleigh Follis 2H

Why is the ground state electron configuration for silver [Kr] 4d^10 5s^1 rather than [Kr] 4d^9 5s^2?

Kyleigh Follis 2H

When an electron moves to its highest energy state, for this example let's say it came from the first energy level. When the electron moves down to a lower energy state, it will lose a certain amount of energy that is quantized to correspond to a certain energy level. If the electron moves back to t...

Kyleigh Follis 2H

The energy of a particle is quantized, meaning it is restricted to a series of discrete values, called energy levels. According to quantum mechanics, because there are boundary conditions on wave functions and each wavelength corresponds to a different energy energy is quantized. Because an electron...

Kyleigh Follis 2H

The orbital angular momentum quantum number (l) corresponds to the orbitals of a shell and the subshells, or group of orbital that have the sam value of l. For example, when n = 3, l can have any of the 3 values 0, 1, or 2. When l = 0, there is an s type of orbital. When l = 1, there is a p type of ...

Kyleigh Follis 2H

Typically reagent is what you point to in the lab.

Reactant is what you point to in the balanced chemical equation.

Although, this distinction is not often made (and not that important).

Kyleigh Follis 2H

Theoretical yield is the maximum yield of a product that is found through calculations. Due to side reactions, impurities, product sticking to the side of walls, human error, etc. during experiments the actual yield will be less.

Kyleigh Follis 2H

Molarity (M) = moles of solute (n) / volume of solution (v) in Liters = mol . L ^-1

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