CHEMISTRY COMMUNITY

beckyolmedo1G

is rate of formation the same as unique rate?

beckyolmedo1G

Ethan Breaux 2F wrote:don't forget if the x value is very small (i.e. less than 10^-3) you can ignore the x when subtracting it from another value!

I thought if K is less than 10^-3 then we can estimate? Not x?

beckyolmedo1G

Thank you!!

beckyolmedo1G

yes! you exclude liquids and solids

beckyolmedo1G

A mixture initially consisting of 0.250 N2 (g) and 0.500 M H2 (g) reacts to form NH3 (g) which is 0.15 M NH3 (g) at equilibrium. Calculate the concentration of N2 (g) at equilibrium for the reaction N2(g) + 3H2(g) ⇌ 2NH3(g) can someone help me find the concentration of N2? Above is everything that i...

beckyolmedo1G

so the unique average rate of each product/reactant is the same exact thing?

beckyolmedo1G

Are we expected to know how to get from the differential rate laws to the integrated rate law for the orders, 0, 1, and 2?

beckyolmedo1G

For a reaction, when OH conc. was doubled, the rate doubled. When the CH3OH concentration alone was increased by a factor of 1.2, the rate increased by a factor of 1.2. Write the rate law for the reaction. The answer key says "rate is 1st order in both reactants." But I thought it would be...

beckyolmedo1G

In order to find n (the number of electrons transferred) write down both half reactions and balance them. You always want to make sure that the number of electrons being transferred is the same amount for both half reactions.

beckyolmedo1G

for this same homework question, how come we don't add H2O in order to balance the OH-?

beckyolmedo1G

How do you identify if a cell diagram needs an inert conductor? Also, which side would you put it on, left or right? Thank you!

beckyolmedo1G

are you sure that oxygen got oxidized? I thought that it remained the same (-2) on both sides.

beckyolmedo1G

When both are negative it would be spontaneous at LOW temps. If both were positive, it would be spontaneous at HIGH temps.

beckyolmedo1G

Thank you!

beckyolmedo1G

I am still confused on what (emf) is. Can someone please explain and what is its purpose?

beckyolmedo1G

What is deprotonation? And how does that relate to Ka2?

beckyolmedo1G

Do the units of delta G always have to be kj/mol or can we leave them in J/mol?

beckyolmedo1G

Thank you!!!

beckyolmedo1G

If a reaction is at equilibrium with deltaH +2.86 kj what would happen if the temperature of the reaction is increased?

beckyolmedo1G

I know that isothermal means constant temperature, but I need help understanding this more too.

beckyolmedo1G

yes, I believe so. When bonds break, energy is required to break the bond so it is positive. However, when bonds are formed, energy is released that is why it is negative. So breaking a bond is endothermic while forming a bond is exothermic.

beckyolmedo1G

A calorimeter was calibrated with an electric heater, which supplied 22.5 kJ of energy as heat to the calorimeter and increased the temperature of the calorimeter and its water bath from 22.45 degrees C to 23.97 degrees C. What is the heat capacity of the calorimeter? What equation is used in order ...

beckyolmedo1G

heat lost by the copper= -heat gained by the water
so, you use the equation (mass of copper)(Tfinal-TInitial of copper)(C)=-(mass of water)(Tfinal-Tinitial of water)(C). Then solve for Tfinal

beckyolmedo1G

I think you should always think about, and apply the rules for sig figs. It's a good habit.

beckyolmedo1G

(a) Calculate the heat that must be supplied to a 500.0-g copper kettle containing 400.0 g of water to raise its temperature from 22.0 degrees C to the boiling point of water, 100.0 degrees C. Why do we need to account for the copper kettle and not just the water in order to find the amount of heat ...

beckyolmedo1G

Although some bases or acids are not on the tables, you can look at their conjugate acid or base and then use the equation Ka x Kb = Kw to find the opposite. For example if you have the conjugate base Kb you would manipulate the equation in order to solve for ka and vice-versa. ka=1.00x10^-14/kb

beckyolmedo1G

Are we supposed to know how the equilibrium equation looks off the top of our heads when given a solution. For example, in the 6th edition book, problem number 12.69 asks to find the ph for the solution .19 M NH4Cl only. And we obviously need the equilibrium equation to set up the ice table. For hom...

beckyolmedo1G

I don't have the 7th edition book but the 6th edition has a similar problem that only gave the initial concentration. What I did was first find ka using the equation ka x kb= kw. Once you find ka you can use the ice table to solve for x. Once you find your x you can plug that into -log(x) which equa...

beckyolmedo1G

Dr. Lavelle has 2 links on his website that explain sig figs. It also shows good examples that might be helpful, if you need more clarification.

beckyolmedo1G

I think it would affect the ratio definitely, but since K is being manipulated it would no longer be K, it would be Q, so I think Q would be the one affected

beckyolmedo1G

I have the same question. I think we would have to factor in the coefficients in the ICE table where we normally account for the change in x. Im not 100% sure though.

beckyolmedo1G

I think doing hw problems is the best way to practice the material. Also, attending office hours is extremely helpful.

beckyolmedo1G

I believe you use Q when you are not sure whether or not the reaction is at equilibrium. Or when K is given and you calculate the ratio and it is a different value than K, therefore you would be using Q.

beckyolmedo1G

When calculating both Q or R you put the products over the reactants.

CHEMISTRY COMMUNITY

Search found 34 matches

Rate of Formation vs Unique Rate

Re: Equilibruim Assessment

Re: Equilibruim Assessment

Re: Equilibrium constants with partial pressures and concentrations?

Equilibruim Assessment

Re: Unique Average Rate

Rate Laws

6th Edition 15.15

Re: Value of n

Re: H+ and OH- in cell diagrams

Cell diagram

Re: redox homework question

Re: Spontaneity in the Gibbs Eqn

Re: Deprotonation

Electromotive force

Deprotonation

Gibb's free energy Units

Re: Test 1 Question

Test 1 Question

Re: isothermal vs reversible

Re: Bond Enthalpies

6th edition Hw problem 8.23

Re: 6th Edition Problem 8.21

Re: Sig Figs with Enthalpy

6th edition hw problem 8.19

Re: Finding Ka or Kb

Setting up Equilibrium Equations

Re: Calculating the pH - 6D.17 7th edition

Re: Sig figs in pH

Re: Removing products

Re: Stoichiometric Coefficients

Re: New to Lavelle

Re: Reaction Quotient Meaning

Re: Calculating Q