Dissociation Definition and 79 Threads

I understand every bond chemically has a length and energy to break, and energy is Newton*meters. Is the Bond enthaply/Bond disassociation energy equivalent to the force needed to break the bond * the bond length? Why don't we say, to break the bond from O to H we need to put magnets on left of...

The problem states that I'm adding a certain volume of a known [KOH] to a certain volume of a known [HCH3COO]. The goal is to calculate the final pH. Since I don't know the K value of the rxn of HA w/ OH-, I set up 2 equations and combined their K values to derive the K value. Since the new...

So I calculated the pH for the two concentrations: pH=4.61 for the high concentration and pH=5.61 for the low concentration. Regarding the dissociation: in the solution manual it is given that the acid is most dissociated at the higher pH than the lower pH, which to me seems strange...

I was wondering whether intense UV light, tuned to the correct wavelength, could be used to split carbon dioxide and water molecules as a first step towards synthesizing liquid fuels.

Homework Statement Calculate an approximate heat of combustion for propane (C3H8) in kilojoules per mole by using the bond dissociation energies in the table. (The strength of the O=O bond is 498 kJ/mol, and that of a C=O bond in CO2 is 804 kJ/mol.) Homework Equations C3H8 + 5O2 → 3CO2 + 4H2O...

I hear that methane is known dissociate into free radicals and sometimes into ions (carbocation and hydrogen proton). Is it different amounts energy responsible for the same molecule (methane) to undergoing different kinds of dissociation?

Why we always say that acid dissociates in water while bases ionizes in water knowing that both gives ions? What is the difference between dissociation and ionization in this field?

If I'm given the dissociation constant for HF, how would I find the dissociation constant for F-? Thanks in advance.

Homework Statement When a weak acid HA is titrated 75% of its endpoint, it has a pH of 5.25. Calculate its Ka. Homework Equations Ka = [H+ ][A- ]/[HA] [H+] = 10^-pH The Attempt at a Solution I found [H+ ] from the pH to be 10^-5.25 M. From the dissociation equation of HA, we know there is a...

Homework Statement Hello all! Say I have an ion XY. I dissolve it in a solution. What is the difference between its dissociation or solubility, or are they the same? Seems my ap chem review book is using these two terms interchangeably and I am just plain confused. Thanks Homework Equations...

What's the unit used to measure α ? if α=(Kd/C)0.5 where Kd is the dissociation constant and C is the total concentration of electrolyte .

Homework Statement Hi, I tried the following task: I tried to solve it, but apparently it's not correct: Can someone show me the right way to do this?Homework Equations See above The Attempt at a Solution see above[/B]

This is more of a biochem question, but since there is not biochem forum, I'll ask it here. How much heat is required to break a peptide bond (not just denature the protein) in the absence of any catalysts?

So I've learned that in strong acids that dissociate completely, the concentration of H+ is the same as the concentration of the initial solution. So 1M of a strong acid will create 1M of H+, meaning the pH is 0. I've also learned that in weak acids, the whole thing doesn't dissociate. I have...

Is there a formula to theoretically determine the number of moles of each ion present when a particular concentration of salt is dissociated in water? I remember from A-level (high school) chemistry that concepts such as the dissociation constant exist but I'm struggling to apply them to...

Homework Statement Hi everyone. I'm a relatively new high school chemistry teacher. I'm teaching modified arrhenius theory to my students, and I'm unclear on ionization vs. dissociation. Homework EquationsThe Attempt at a Solution Here is my understanding: - Dissociation occurs when an ionic...

Homework Statement How much does the auto - dissociation of water contribute to the pH a 10e+3M aqueous solution of sulphuric acid? Homework Equations Ka = [H30+][SO42-}/[HSO4-] = 1.1e-2 Kw = [OH-][H30+] The Attempt at a Solution Sulphuric acid is a strong acid in the first hydrolysis step...

Hello everyone, Sorry I didn't have the time to rewrite the question, Can you help me with this?

Homework Statement when 10 cm3 of a monoprotic acid C3H6O3, with concentration of 7.2g/dm3, was titrated against against 0.05M NaCl, the equivalence point reached when 15.75cm3 (ph8) of NaOH was used. Calculate the acid dissociation constant Ka for C3H6O3. Homework EquationsThe Attempt at a...

Homework Statement For given general reaction 2A<->A2 the affinity constant is known k(T)=1.7 10-4 mol/cm3 (t=18 C) Find dissociation (constant) level in normal pressure. Homework Equations So i solved it - found the general solution for dissociation constant. alpha=1/(sqrt(1+4k)) Now i have...

Homework Statement Barbituric acid is a single proton organic acid. Assume it is called "HA". Results show pH 4.22 in a solution of 0.020mol/dm3 of barbituric acid and 0.030mol/dm3 for sodium barbiturate, NaA. Calculate the "acid dissociation constant" for barbituric acid. Homework...

NaOH dissociation is exothermic so ΔH<0 But when I have a reaction NaOH(s) => Na+(aq) + OH-(aq) and count ΔrH using standard entalphy change of formation: ΔfH (NaOH) = -425 kj/mol ΔfH (OH-(aq)) = -230 kj/mol ΔfH (Na+(aq)) = +242 kj/mol Data from Atkins phisical chemistry basics...

I have read there is a way to dissociate water without use of an electrolyte by means of high voltage that overcomes the dielectric constant of water. Would it therefor be possible to economically retrieve water from any depth well by dissociating the water at the bottom of the well into...

Hi, Can you look at the answers sheet of my notes? There seems to be a mistake with the maximum solubility of PbI2. Why do they not divide by two? I get 0.000187M.

Is the degree of dissociation the value of Alpha when the dissociation begins with 1 mole of the solute, or is it alpha when the solute is 1 mole at equilibrium, There isn't a difference since I'm talking about very weak electrolytes but I want to know the accurate answer.

Hello i want to solve a complex integral that in one of the first step its better to dissociation fraction.i want to know how can dissociation main fraction to two separate fraction and find "? " ? Thanks

Homework Statement In a particular solution, acetic acid is 11% ionized at 25 degrees Celsius. Calculate the pH of the solution and the mass of acetic acid dissolved to yield 1.00 L of solution. Ka of CH3CO2H: 1.8x10^(-5) Homework Equations Ka=([CH3CO2-][H3O+])/[CH3CO2H] pH=-log[H3O+] The...

Homework Statement Vapour density of N_2O_4 which dissociated according to the equation N_2O_4(g) \Leftrightarrow 2NO_2(g) is 25.67 at 100°C and a pressure of 1 atm. Calculate the degree of dissociation and K_p for the reaction Homework Equations The Attempt at a Solution \alpha =...

Ka = [H+][A-]/[HA] Is the term "[HA]" referring to its initial concentration or its equilibrium concentration?

What are the dissociation constants of NaCl and KCl respectively? I want to determine how much of the salt dissociates in a 1 M solution. Thanks!

I can quickly calculate the dissociation degree of a monoprotic acid with the formula below (derived from the Hendersson-Hasselbach equation). I don't see any reason why this would not work also for polyprotic acids but I would like to confirm that it does. I would appreciate it if someone could...

Hey guys, Combustion in an SI engine. So an AF:R of 14.7:1 is stoichiometric for petrol (gas), but an AF:R of 12.5:1 makes more power. One common thought is that not all the fuel and oxygen react in a stoichiometric mix, so by upping the fuel there is more chance of all the oxygen...

Hi, Does anyone know where I can find post-hartree-fock calculation benchmarks for dissociation energy of the NO molecule. Or even just the equilibrium energy of the NO molecule? I am looking for cc-pVTZ basis set results but I can only seem to find augmented basis set results. Thanks.

Homework Statement The potential energy of two atoms in a diatomic molecule is approximated by U(r)= ar^{-12} - βr^{-6}, where is the spacing between atoms and α and β are positive constants. From earlier parts of the equation, it has been that determined that force between two atoms as a...

Hi, I have been searching the net but couldn't find the dissociation energies of Cr2Cl3 & Cr2O3... Just knowing which is higher will suffice too & is there any other molecule with lower dissociation energy which could lead to Cr3+ ? Many thanks in advance.

Hi Everyone, I was just wondering if you know of any factors that would affect the dissociation of a strong acid. I know that weak acids are affected by factors such as the common ion effect and temperature, but would this apply to strong acids as well? I only ask because we added...

I'm preparing for a chemistry lab relating to "Determination of the dissociation constant of a eak acid". In part of the lab, I will b doing the following for measuring "Ka" for ethanoic acid using the indicator method: 1- Mix ethanoic acid (0.02M, 5cm3) and sodium ethanoate (0.02M, 5cm3)...

This is probably an easy question, but I can't get it straight and searching has not helped. So when salts go into solution they completely dissociate if they contain anions of strong acids or cations of strong bases, right? I'm still shaky on this concept though. Take Sodium carbonate for...

Pure water is made up of water molecules, no free moving ions. However, if you add an ionic compound, say copper sulfate into water, Cu2+ and SO42- will be produced, so will H+ and OH- ions. Why will water molecules dissociate into hydrogen and hydroxide ions when an ionic compound is added...

In a textbook, HCl is said to remain as molecules in liquid ethanol. However, I still wonder whether HCl dissociates in ethanol to give H+ and Cl- ions. I think that as ethanol contains an OH group which is polar, ethanol molecules are capable of breaking the bond H-Cl in a manner similar to...

Hi, Suppose there are two plasma cases, conditions are the same, except for the gases present: a-Oxygen b-Nitrogen Since the dissociation energy of nitrogen is higher than oxygen, what could be concluded from it? Could it be more energetic nitrogen ions than oxygen ions (because initially...

why do acids and bases dissociate into ions while in water?

Homework Statement Beam of excited H2 molecules travels in z direction, kinetic energy 1 eV.Then they decay & dissociate into 2 H-atoms.When one of the H atom has its final velocity perpendicular to z axis, its kinetic energy is always 0.8eV. Then what is the energy released in dissociative...

Hi! If you use an electron beam on hydrogen gas and when the energy of the beam is 22 eV H+ start to appear, how can you calculate the dissociation energy of H2 using that information? I've tried: 22 eV = D + "ionization energy of a H atom" etc, but couldn't make it add up. I would be...

Homework Statement At 627 C and 1 atm pressure, SO3 partially dissociated into SO2 and O2 by SO3--->SO2 +1/2O2. The density of equilibrium mixture is 0.925g/L. What is the degree of dissociation? Homework Equations The Attempt at a Solution I found out the average molecular...

If a diatomic molecule's vibrational energy is increased to the dissociation energy of that molecule, will that cause the molecule to rip itself apart? Is it the change in vibrational energy that causes the molecule to dissociate?

Acid dissociates in water to form H3O+ and OH- but the formal charge on the oxygen atom in H3O+ is +1. Shouldn't the oxygen atom have a negative formal charge since it is more electronegative than hydrogen atom?

This is probably something I should know, but I don't want to wait and ask my professor. In the combustion of H2, assuming O2 is plentiful enough not to be a limiting reactant, H2O forms as a result of the O-H bond being more stable than the bonds between two H or two O. Is this due to the...

Homework Statement In my lab, it says that i have to calculate the pH and the Ka of an unknown acid of known concentration (0.20 mol/L)..however, the part that is confusing me is that we first had to obtain 40 mL of that particular unknown acid... Homework Equations The Attempt at a...

Has anyone heard of this, is it bad?