CHEMISTRY COMMUNITY

Aarushi Solanki 4F

Because k is directly proportional to temperature, it would increase with an increase in temperature.

Aarushi Solanki 4F

A glass electrode is an example of an ion-selective electrode, meaning that it detects the concentration of a specific ion. pH meters are usually glass electrodes.

Aarushi Solanki 4F

Because K, the equilibrium constant, is equal to the forward rate divided by the reverse rate, knowing K and the forward rate will give you the reverse rate.

Aarushi Solanki 4F

They are the same type of cell, at least in the context of this class.

Aarushi Solanki 4F

Changing the size of the electrode doesn't change cell potential, but it will change the "battery" life.

Aarushi Solanki 4F

Standard E cell will not change but E cell itself will change. The equation E = E* - (RT/Fn)lnQ, where Q involves concentrations of reactants and products, shows that concentration affects E cell.

Aarushi Solanki 4F

Isochoric indicates a constant volume and isometric indicates equal dimensions.

Aarushi Solanki 4F

w is positive when work is done on the system and w is negative when the system does work.

Aarushi Solanki 4F

The voltage of the cell is related to the concentrations as seen by the equation E = E* - (RT/Fn)lnQ. Q is concentration-dependent, so E is concentration-dependent.

Aarushi Solanki 4F

Standard Gibbs Free Energy is defined for given reactions at standard conditions. Gibbs Free Energy is the actual energy available to do work at whichever stage of the reaction its in, and therefore changes as the reaction progresses.

Aarushi Solanki 4F

You only consider the atom within the molecule because although molecules do have overall charges, the oxidation number of the atom will change with respect to which molecule its in as a reactant versus as a product.

Aarushi Solanki 4F

The units for a zeroth order reaction is M/s, or mol/(L*s).

Aarushi Solanki 4F

Because the slowest step is the rate determining step, in the sense that it is able to be measured within a time interval, fast reactions are not included in rate laws.

Aarushi Solanki 4F

When you use the two delta G equations and set them equal to each other (deltaG = - RTln(K)) and (deltaG = -nFE), you can derive the Nernst equation

Aarushi Solanki 4F

If there was no salt bridge, the anode solution would be very positive and the cathode solution would be very negative and the reaction would stop. The salt bridge neutralizes some of the positive ions produced in the anode using the anion of the salt and the negative ions produced at the cathode us...

Aarushi Solanki 4F

It's supposed to be in Kelvin. Generally, we use Kelvin, but it is okay to use Celsius in equations involving the "change of T" since the scaling is the same for Kelvin and Celsius.

Aarushi Solanki 4F

Yes. This makes sense because the "reducing agent" is the one that causes reduction, meaning that it "gives" the reduced species electrons to gain. To "give" these electrons, it must first lose electrons, or be oxidized.

Aarushi Solanki 4F

The salt bridge neutralizes both solutions in a sense, so they don't quickly reach equilibrium. By "neutralizing," I mean that if a cation was being produced in one solution, the anion portion of the salt in the salt bridge would neutralize this positive charge.

Aarushi Solanki 4F

Balancing the half-reactions simply means separating the reduction process and oxidation process from the original reaction into two half-reactions, and then balancing these resulting reactions.

Aarushi Solanki 4F

The oxidizing agent gets reduced, which means that it gains electrons. The reducing agent gets oxidized, which means that it loses electrons.

Aarushi Solanki 4F

If it's an acidic solution, you add H+ ions to balance the H's. If it's a basic solution, you add H2O and OH- ions to opposite sides to the equation in equal moles to balance the H's.

Aarushi Solanki 4F

You use 8.314 when the units are J/(mol*K). You use 0.08206 when the units are (atm*L)/(mol*K).

Aarushi Solanki 4F

Kelvin, because the gas constant R is usually in terms of Kelvins.

Aarushi Solanki 4F

If the question specifies a temperature unit then use the given one. Otherwise, remember to perform your calculations with like-temperature units, so they correctly cancel out based on ratios.

Aarushi Solanki 4F

No work is being done at equilibrium and delta g represents the energy left to do work. Therefore, delta g is 0.

Aarushi Solanki 4F

Adding inert gases increases the pressure of the system but doesn't affect the concentrations at equilibrium.

Aarushi Solanki 4F

You can disregard x when K is less than 10^(-3) because it will be an extremely small value that won't affect your calculations. However, to ensure that you were correct in disregarding the x value, you must check if x is less than 5% of the original solution's concentration.

Aarushi Solanki 4F

Work isn't a state property because the energy used when doing work is different based on the path to achieve the final state. When expansion work occurs reversibly, more work is done than if it were to be done irreversibly.

Aarushi Solanki 4F

Density is given in g/mL. Sometimes, the problem gives the amount of a substance in mL, and you can convert this value to grams and then moles to find the 'n' in PV=nRT.

Aarushi Solanki 4F

A reaction is spontaneous when Gibbs Free Energy is negative.

Aarushi Solanki 4F

There's no direct relationship between these two concepts. State functions are simply properties that don't consider the path taken to achieve a given state, only considering the final state itself. Extensive properties are properties that change based on the amount of matter present. For example, h...

Aarushi Solanki 4F

The method for checking whether your approximation is valid is by calculating whether the percent ionization/deprotonation is less than 5%.

Aarushi Solanki 4F

A high value of entropy means that there is a lot of disorder in the environment. For example, gases have a higher entropy than solids as there is increased disorder in the positions, or micro states, gases exist in. Another example is when a reaction occurs and the number of moles of substance incr...

Aarushi Solanki 4F

Kp is used when the quantity of gases are given in context of pressure. Kc is used when the molarity of solutions or gases are given.

Aarushi Solanki 4F

Standard form of the substance is the form that a substance naturally occurs as in 25 degrees Celsius and 1 atm conditions. The most important thing to remember about standard form is that some molecules exist in their diatomic form at these conditions.

Aarushi Solanki 4F

Extensive properties are those that depend on the amount of matter. Examples include mass and volume; mass increases as the amount of matter increases, and volume does the same. Intensive properties, such as melting point and boiling point, do not depend on the amount of matter present.

Aarushi Solanki 4F

Delta U indicates internal energy, and is composed of both delta H (enthalpy) and work. When no work is done, Delta U is equal to delta H. When no energy is transferred through heat and delta H is therefore 0, then Delta U is equal to work.

Aarushi Solanki 4F

If the heat capacity is given, the m and n aren't in the equation. This is because specific heat capacity is given per mass unit, molar heat capacity is given per mole, and heat capacity is simply J/K.

Aarushi Solanki 4F

Only the numbers after the decimal matter when determining the number of significant figures to add. For example, if two sig figs are used in the question, then the answer should have two significant figures AFTER the decimal (ex: 5.41).

Aarushi Solanki 4F

It is asking whether the concentration of the products when the reaction is at equilibrium will be higher when more of the reactants are added to the reaction.

Aarushi Solanki 4F

Inert gases don't interact with anything, which indicates that the initial concentrations remain the same after the addition of the inert gas.

Aarushi Solanki 4F

The cations and anions of strong acids and bases don't play a role in affecting pH and are not included in equilibrium concentration.

Aarushi Solanki 4F

To get the new Kc, you multiple the two original Kc's together.

Aarushi Solanki 4F

Because the Ka for the second deprotonation is very small, it doesn't have a substantial effect on pH.

Aarushi Solanki 4F

The equilibrium constant varies with changing temperatures.

Aarushi Solanki 4F

Q, a variable, describes the same reactant-product relationship as K, except K is a constant where Q=K would represent the reaction at equilibrium.

Aarushi Solanki 4F

It is on the equation sheet but you should understand the reasoning behind the derivation of this equation.

Aarushi Solanki 4F

If the partial pressure of one of the reactants increases, then the reaction will shift right and produce more products, increasing the products' partial pressures. The partial pressure of the other reactants therefore decreases.

Aarushi Solanki 4F

If the forward reaction (more product produced) is naturally favored, then the product is more stable.
If the reverse reaction (more reactant produced) is naturally favored, then the product is more stable.

Aarushi Solanki 4F

K is the equilibrium constant, and a reaction naturally shifts with the goal of reaching equilibrium. So, although Q is representative of the actual system, the ideal state is Q=K.

Aarushi Solanki 4F

Shift left means that more reactants will be produced so the reaction progresses to Q = K.
Shift right means that more products will be produced so the reaction progresses to Q = K.

Aarushi Solanki 4F

Pascals are generally used as the unit for pressure, but the conversion is 1 bar=10^5 Pa

Aarushi Solanki 4F

The quick way you're referring to has to do with changes in pressure. The basic rule is that when pressure increases (volume decreased), the reaction will want to shift to the side (reactant vs. product) with less total moles. When pressure decreases (volume increased), the reaction will shift to th...

Aarushi Solanki 4F

Lone pairs impact the bond angle due to lone pair-bonding pair repulsion, decreasing the angle.

Aarushi Solanki 4F

As long as you understand the concept behind the properties of acids and their impact on pH and pOH, you will be able to answer the question as there won't be specific calculations or anything in 14A.

Aarushi Solanki 4F

No, it is simply an intermolecular force.

Aarushi Solanki 4F

In a cis molecule, the "function" atoms/molecules (e.g. Cl in cisplatin) lie on the same side, whereas in trans molecules, they are opposite of each other.

Aarushi Solanki 4F

It is asking for the formula AXbEc, where A is the central atom, X is a ligand (unspecific) with subscript b as the number of ligands attached to A, and E indicates a lone pair with subscript c describing the number of lone pairs on central atom A.

Aarushi Solanki 4F

Yes, you can use the abbreviations.

Aarushi Solanki 4F

T-shape molecule is AX3E2, indicating that there is a central atom with two axial atoms and one equatorial atom, that together resemble the letter T.

Aarushi Solanki 4F

Yes, because pi bonds are formed by the overlapping of two unhybridized p-orbitals.

Aarushi Solanki 4F

It binds to the two consecutive N atoms' lone pairs. Each G has a nitrogen atom with a lone pair and the Cl on cisplatin is attracted to it.

Aarushi Solanki 4F

A single bond has one sigma bond.
A double bond has one sigma bond and one pi bond.
A triple bond has one sigma bond and two pi bonds.

Aarushi Solanki 4F

You do not have to add anything for a positively charged one.

Aarushi Solanki 4F

NaCl is an ionic compound and therefore doesn't involve the sharing of electrons. So, there is no bond formed because a bond is the overlapping of orbitals.

Aarushi Solanki 4F

An amphiprotic molecule can act as both an acid and a base.

Aarushi Solanki 4F

Sigma or pi bonds are not formed in an ionic compound because sigma and pi bonds are the result of the sharing (and therefore overlapping) of electrons in only covalent compounds.

Aarushi Solanki 4F

Strong acids almost completely dissociate into the ions, whereas weak acids only partially dissociate into the respective ions.

Aarushi Solanki 4F

Kb is the base dissociation constant, so the higher the value is, the stronger the base is. Kb multiplied by Ka should give Kw, the dissociation constant for water (at equilibrium). So, Kb = Kw/Ka.

Aarushi Solanki 4F

The value of kA is the acid disassociation constant for a reaction at equilibrium. Essentially, this means that kA is the ratio of concentration of products (multiplied) to concentration of reactants (multiplied) when these values are in the equilibrium state.

Aarushi Solanki 4F

The lower the pH is, the stronger the acid is. This is because pH decreases with the increase of H+ ion concentration, and a greater presence of H+ when compared to OH- indicates base-like properties.

Aarushi Solanki 4F

Yes, this is possible when the H+ concentration is greater than 1.

Aarushi Solanki 4F

Interaction potential energy relies on the charges of the two molecules and the distance between them. As distance increases, potential energy decreases. As charges of the molecules increase, potential energy also increases. This can be seen by the relationships in the equation.

Aarushi Solanki 4F

A single bond is a sigma bond. A double bond is one sigma bond and one pi bond. A triple bond is one sigma bond and two pi bonds.

Aarushi Solanki 4F

I start out by drawing a Lewis structure and determining whether the compound is polar. If it's polar, it will experience dipole-dipole interactions. If it has an H bonded to an F, O, or N, it experiences H-bonding. If it's non polar, it only experiences London Dispersion Forces.

Aarushi Solanki 4F

No, because it is the same compound and resonance isn't reality. Reality is the intermediate of all the resonance structures.

Aarushi Solanki 4F

Hydrogen bonding is the strongest form of dipole-dipole interaction. London dispersion forces are the weakest form in a sense as it is the result of two induced dipoles interacting.

Aarushi Solanki 4F

Try not to memorize but to visualize all the VSEPR structures. Understand the mechanisms behind each structure and it'll be easier to remember all of them.

Aarushi Solanki 4F

"Bent" and "angular" are the same shape, but I believe "angular" is the preferred term for this class since the solutions manual refers to the shape as "angular."

Aarushi Solanki 4F

It doesn't matter if an atom is bonded vertically or horizontally to the central atom per say, but those could be the different resonance structures for the same molecule. The structure that is most stable is the one with formal charges closest to zero and the negative formal charges being on the mo...

Aarushi Solanki 4F

You usually cannot simply look at the molecular formula and determine its polarity. It's important to look at the lewis structure, and even the molecular shape. For example, the lewis structure for CH2Cl2 seems symmetrical from a 2-D perspective; however, because it is tetrahedral, the dipoles don't...

Aarushi Solanki 4F

A molecule is polar if there are dipoles that don't cancel each other out, making a specific part of the molecule more prone to having a higher electron density (usually near a more electronegative atom). A simpler way to look at this is determining whether the molecule is symmetrical (the element o...

Aarushi Solanki 4F

An electronegativity difference of more than 2.5 indicates that the bond is ionic. An electronegativity difference less than 1.5 indicates that the bond is covalent. An electronegativity difference between 1.5 and 2.5 indicates that the bond has ionic and covalent character.

Aarushi Solanki 4F

n is the energy level of the electron. l is the number of subshells and describes the shape of the orbital, and can have the value of 0, 1,...(n-1). ml describes the orientation of the orbital, and its values range from -l to l. ms describes the direction of spin of the electron, and can be 1/2 or -...

Aarushi Solanki 4F

The central atom is typically the least electronegative atom.

Aarushi Solanki 4F

The four quantum numbers are used to essentially describe an electron. 'n' describes its energy shell, 'l' describes the shape that electron density can be found in, 'ml' describes its orientation, and 'ms' describes spin state.

Aarushi Solanki 4F

Yes, usually you have to draw all the resonance structures and indicate the most stable one, or the one with the least formal charge.

Aarushi Solanki 4F

When electron affinity is negative, it indicates that energy was released which means an electron was added. When electron affinity is positive, it indicates that energy was absorbed, which is required when actually producing an anion.

Aarushi Solanki 4F

It is harder to remove a second electron because removing the first electron gave the atom (now ion) a positive charge. This indicates that the pull of the nucleus is strong because less electrons means less electron-electron repulsion, resulting in the radii slightly decreasing, and therefore causi...

Aarushi Solanki 4F

Electron promotion occurs when an electron is excited (absorbs energy from a photon) and jumps to a higher energy level.

Aarushi Solanki 4F

Yes - essentially, the more electrons there are, the more electron repulsion there is. This inherently increases the radius. However, there are more factors affecting this than the number of electrons, such as the pull of the nucleus which is determined by the number of protons and the number of cor...

Aarushi Solanki 4F

An atom (ex: P, S) is said to have an expanded valence shell if it has more than an octet (8 valence electrons). This is only possible when the valence shell has enough orbitals to "make space" for the extra electrons.

Aarushi Solanki 4F

Yes, the one-electron model is only applicable to H-atoms. All other atoms will have more than 1 electron, rendering it a multi-electron atom.

Aarushi Solanki 4F

"c" (speed of light) can never be replaced by "v" (velocity) because "c" is a constant which is known and "v" is a variable which is unknown.

Aarushi Solanki 4F

Yes, that equation is specific to a "one-electron" model, and this model is only possible with a hydrogen atom.

Aarushi Solanki 4F

Hertz essentially indicates how many "cycles" of the wave have passed a certain point in one second. In simple terms, 1Hz = 1cycle/second. The "cycle" is implied.

Aarushi Solanki 4F

Yes, the speed of light (2.998*10^8 m/s) is always a constant, as long as this light is traveling in a vacuum-like medium.

Aarushi Solanki 4F

Wavelength and frequency have an inverse relationship. Amplitude is unrelated, but an increase in amplitude indicates an increase in the intensity of the energy.

Aarushi Solanki 4F

The intensity of light, when looking at the wave model, depends on how large the amplitude of the wave is. When looking at it based on the quantum model of light, a higher intensity means more photons are involved.

Aarushi Solanki 4F

Speed of light is a constant depending on the medium it travels through. The "c" speed of light constant indicates the speed of light in a vacuum.

Search found 107 matches