CHEMISTRY COMMUNITY

Ritu Gaikwad 2E

With heterogenous catalysts we would have to consider the adsorption and change due to the varying physical states of the substance.

Ritu Gaikwad 2E

I believe that we were told by Dr. Lavelle to not use the steady state method and instead use the pre-equilibrium method that he taught us in class. The pre equil method involves looking at the rate laws of the intermediate reactions and seeing whether or not those rate laws match up with the given ...

Ritu Gaikwad 2E

If the catalyst was saturated with just reactants, then the catalyst would be the main driving force of the reaction and it would only be dependent on reaction rate, or k, in a zeroth order reaction. This would be possible in a real life reaction if the catalyst was saturated completely and the conc...

Ritu Gaikwad 2E

Thermodynamics is focused on the transfer of heat or energy in a reaction, focusing primarily on the beginning and ends of the state of a reaction while kinetics is focused on the actual speed of the process taken to get to that reaction.

Ritu Gaikwad 2E

You can look at the rate of change of one species and how that is related to another by looking at the unique rate law which takes into account the actual stoichiometric coefficients and tells you each unique rate.

Ritu Gaikwad 2E

As said earlier, an elementary reaction is simply breaking down the reaction into a series of intermediate reaction steps which can be combined in order to write the rate law. The benefit of writing out elementary reactions is that the reaction that occurs in the slow step is the rate-determining st...

Ritu Gaikwad 2E

The units of k is determined by the rate of the reaction and the order of the reaction determines the units for K.

Ritu Gaikwad 2E

I believe with equilibrium to determine whether or not the concentration was negated out of the equilibrium expression the lower bound limit was 10^-3 and could possibly be 10^3 for the upper bound limit although I'm not sure if it would be the same for kinetics.

Ritu Gaikwad 2E

The rate constant, regardless of the order of the reaction will not be dependent on the coefficients of the reaction.

Ritu Gaikwad 2E

For the slow step the actual reaction that determines which step is the slow step is the intermediate reaction right before the slow step.

Ritu Gaikwad 2E

For kinetics you should be looking at how the reaction is progressing by looking at the rates and the actual pathway of the reaction. For thermodynamics you should be looking at the initial and final rates and making sure you understand the energies involved with both of them.

Ritu Gaikwad 2E

The order of a reaction explains how that reaction rate varies depending on how the reaction is organized. For example if it was a zeroth order reaction then there would be no correlation between reaction rate and time and first order would have a direct correlation and so on.

Ritu Gaikwad 2E

I would focus on making sure you understand what concept is being relayed by each equation and what variables are required and that should give you a better way to memorize.

Ritu Gaikwad 2E

I don't think it is a coincidence because there is the same species in both cells so it would make sense to assume a concentration cell.

Ritu Gaikwad 2E

I believe you should not just be looking at standard reduction potentials when comparing metals, but rather where they are located on the periodic table. If elements are near the bottom left they are good reducing agents as they are metals that want to lose electrons whereas if you look at the top l...

Ritu Gaikwad 2E

If the n is not given, look at the half reactions and find the number of moles of electrons transferred and that is your n value because that is what n stands for in the equation.

Ritu Gaikwad 2E

It depends on the half reactions and whether or not that is considered an anode or a cathode reaction as at the anode there is oxidation and at the cathode there is reduction but the main reason anodes are written on the left and cathodes on the right is to stay consistent with the cell diagram nota...

Ritu Gaikwad 2E

When a reaction is spontaneous and the delta G is negative that means that free energy is available and not required in order for the forward reaction to occur.

Ritu Gaikwad 2E

Platinum would be included as an anode because it is used as a salt bridge in the galvanic cell in order to rebalance the respective charges of the solutions and allow the transfer of electrons to proceed.

Ritu Gaikwad 2E

The importance of a galvanic cell is that charge is being transferred from one species to another, or from anode to cathode and as electrons are transferred from one species to another there is a buildup of charge and a voltage associated with that. Therefore electricity is generated when electrons ...

Ritu Gaikwad 2E

With species that have the same oxidation number you have to make sure to balance the reaction with waters and adding in ions or electrons in order to create a balanced half reaction. Once that is done you can settle your balanced reaction.

Ritu Gaikwad 2E

When you're looking at oxidation and reduction think about whether that species will be gaining or losing electrons and depending on what is happening that will be the agent. In terms of balancing redox reactions you have to add species like H20 or H+ or OH- depending on the solution type.

Ritu Gaikwad 2E

The first part of the statement, that removing heat from a system will be exothermic is true because heat is leaving the system. However as said before phase changes play a role in not changing temperature because heat can be added to go from one phase to the next but not change the temperature in a...

Ritu Gaikwad 2E

In a reversible system the entropy of the system and the surroundings are equal and opposite to each other making the net entropy zero because the change in one aspect (the system) will be matched by changes in its surroundings to make sure the pressure internal and external are approximately equal ...

Ritu Gaikwad 2E

The Delta G with the degree sign is the one being calculated because this is under standard conditions for the reaction and correlates to a standard enthalpy and entropy and is calculated that way.

Ritu Gaikwad 2E

Outside of what differences have already been distinguished, an isolated system is where the change in internal energy is equal to zero because the amount of work the system is doing or being done on is equal to the replacement of heat by the surroundings. Thus when q and w are equal there is no cha...

Ritu Gaikwad 2E

I'm not sure about the specific problem that Lavelle went over in class where the work and heat would be equal to zero during combustion, but according to the textbook a bomb calorimeter is NOT an isolated system but a closed system. This is because even though it doesn't exchange matter with the sy...

Ritu Gaikwad 2E

I would first look at pV=nRT for to solve for the temperature if all of that info is given but if not then I would just go with standard conditions at 298 K.

Ritu Gaikwad 2E

For free expansion there is no work being done because it is done in a vacuum state and thus it is zero for work.

Ritu Gaikwad 2E

I believe you should not think about the equations as when to memorize when to use them but think about the process itself and what is changing versus staying the same like in reversible the temperature isn't changing so therefore you can't use the temperature change equation but for volume that wou...

Ritu Gaikwad 2E

When looking at entropy change if it is negative then the reaction is is moving toward order and fewer micro-states whereas with a positive entropy there are more micro states and a higher entropy.

Ritu Gaikwad 2E

When the internal energy is equal to the negative change in enthalpy this means that it is a exothermic reaction and the products are releasing heat and are being favored.

Ritu Gaikwad 2E

In terms of calculation is it helpful to draw out diagrams to tell which bonds are being created and being formed, What’s the best way to approach these type of problems?

Ritu Gaikwad 2E

I think you just have to understand how they relate to the heat capacities of reactions depending on constant volume or pressure.

Ritu Gaikwad 2E

When looking at compounds such as NO and NO2 how do you tell between which one will have a larger heat capacity? Does this have to do with the type of bonding occurring in the compound or size? Or something else entirely?

Ritu Gaikwad 2E

I would start from understanding the underlying concepts behind heat, work, enthalpy and how one concept relates to another and that will help you form those equations and prevent you from stressing about it!

Ritu Gaikwad 2E

Why is it that when a reaction is at constant volume the measurement of enthalpy is the change in internal energy versus when the reaction is at constant pressure the enthalpy is the same as heat transfer?

Ritu Gaikwad 2E

A state property can be described with something like enthalpy, which describes the ending and the starting states but there is no relevance of the process of how fast the reactant makes the product.

Ritu Gaikwad 2E

The enthalpy of the reaction for glucose in a combustion reaction versus one with cellular respiration is completely dependent on what the other reactants it is interacting with and the relative bond energies of those reactants and products.

Ritu Gaikwad 2E

When Dr. Lavelle was talking about phase changes, he was saying that in the standard state all substances should be a gaseous phase so if some of your reactants are in a liquid or solid phase you have to factor in an extra heat of vaporization or an extra enthalpy value in order to account for the p...

Ritu Gaikwad 2E

Another thing for method 3 is that when you are calculating the change in enthalpy you have to make sure your equation is balanced and all your substances are in their standard states.

Ritu Gaikwad 2E

The difference between standard reaction enthalpy and standard enthalpy of formation is that the standard enthalpy of formation is for a substance in its standard state (or in the element's most stable form) whereas standard reaction enthalpy by itself doesn't specific the phase of the substance.

Ritu Gaikwad 2E

In addition to what has already been said, it also means that if there is a stronger acid there will be a weaker conjugate base to accompany it and this is especially relevant in the example with water. With water the acidic and basic components have to balance off of each other in order to maintain...

Ritu Gaikwad 2E

The 5% rule is used normally in indicating if when setting up the Kc expression if x should be factored into the concentration of the initial reactant. You normally approximate without using that x and if the resulting value x/(initial conc) is less than 5% it is valid to not factor that x in the co...

Ritu Gaikwad 2E

When looking at an expression you should first determine if it is an endothermic or exothermic reaction and depending on that you can determine how the reaction shifts. When looking at how heat moves around we know that endothermic reactions require heat in the forward direction, and the opposite wo...

Ritu Gaikwad 2E

For the acids and bases, do we have to memorize the list of strong acids and bases for future tests and exams?

Ritu Gaikwad 2E

When calculating percent protonation, do you calculate the concentration of hydronium/hydroxide ions divided by the concentration of the acid/base or is it the concentration of the conjugate base divided by the concentration of the acid/base?

Ritu Gaikwad 2E

What reactions describe when Q=K or is a reaction even present when there is the same amount of product and reactant?

Ritu Gaikwad 2E

For total partial pressures, they are normally calculated when factoring in all of the different contributions to the pressure of the gas and only then is the total used in the ICE table for equilibrium.

Ritu Gaikwad 2E

I don't believe that you can combine two solids together or pure liquids together because based on their properties there might just be a mixture formed as there is not an actual chemical change in either reactant to produce the product. This is why looking at aqueous solutions or gases is important...

Ritu Gaikwad 2E

When we were talking about limiting reagents, we were not looking necessarily at reactions at equilibrium and we had to find the reactant that would limit the use of the other reactants for the reaction to proceed. This relates to equilibrium because once you find the limiting factor you can ensure ...

Ritu Gaikwad 2E

The only external factors that impact K would be temperature because that can impact how much of the reactant is produced or product is created as well. Other factors such as the change in pressure or volume would not affect the K value because the system would adjust concentrations of products and ...

Search found 52 matches