Bond Definition and 324 Threads

Hello! Is it possible to pressurize a substance and break its bonds? Thanks!

Is there a period trend for bond enthalpy? Specifically Atom-Hydrogen bonds. Need to find a trend in predicting the bond enthalpy of several atom-hydrogen bonds I calculated using gaussian. Any help would be appreciated, thanks!

Homework Statement : [/B]The correct relation is: A. x=y B. x>y C. x<y D. None. Please refer to picture attached.Homework Equations : [/B]As stability increases, bond length decreases. When a Π bond is delocalised i.e it takes part in resonance, stability increases.The Attempt at a Solution I...

Our text says that ionic bonds are much weaker in aqueous solutions than covalent bonds, due to the dissociative properties of most ionic compounds in water. I read elsewhere though, that in general, ionic bonds are stronger due to the increased polarity. So, in protein folding, when different...

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 was wondering whether it is possible for amino acids that end up in a cell (ready to be made into proteins) to spontaneously start to bond in the cytoplasm (or wherever the routing channel is I guess) and create randomly floating short strands of polymers? Furthermore, can it ever happen that...

Guys, a certain chemical phenomenon known as hyperconjugation in which carbonium ion which is tertiary or secondary or primary in nature then the pi bond formed for stabilizing effect can be defined as a co ordinate bond or not?

I know that in acetone the central carbon atom is ##sp^2## hybridized. It is bonded to the single oxygen atom with a ##\sigma##-bond and a ##\pi##-bond. But what is the bond type with the two C-C bonds? The lower carbon atoms are ##sp^3## hybridized and so their geometry is tetrahedral. Are the...

I'm having trouble understanding the definition of bond energy. My textbook defines it as the energy required to break 1 mole of the bond in the gas phase. I don't understand what it means to break 1 mole of a bond. Cl2 (g) ---> 2 Cl(g) Bond energy = 243 kJ. Since 1 mole of Cl2 is 1.2*1024...

Edit: thread moved by mod from non technical forum, hence lack of the template. Using arguments from MO theory, state why the trends in homonuclear bond energies for rows 1 and 3 of the periodic table in graph D differ so markedly. S State, with reasons, whether Si or Ge has the higher...

The kinetic theory says that temperature is the measure of the average kinetic energy. That would mean then : The temperature rises with the rise in kinetic energy. We know that when matter changes state 'latent heat' helps in 'breaking the bonds' at the transition phase and that this 'extra...

"When we supply bond energy to two molecules that have bonded, the potential energy of the molecules increase causing the molecules to break bonds." -Is this the correct explanation regarding bond energy? If not, kindly explain this process to me, it's very confusing.

Hello, I performed an optimization and frequency calculation at the ub3lyp 6-311g level of theory. The compound has the formula C39H41PS2. Using Molden, I am having a hard time identifying the frequency corresponding to the stretching of a phosphorus carbon double bond present in the molecule. I...

Hello, in ice I have read that the average bond length of the hydrogen bond is about 2 Angstroms. This is roughly twice the O-H (covalent) bond length. My question is what really determines the length of the hydrogen bond? Why wouldn't the hydrogen be drawn closer to the next water...

In a covalent bonded molecule, what is the force responsible for the molecule staying together. To my knowledge it's to do with electrons of opposite spins and being at a lower energy with valence shells filled but what is the force itself that pulls a second atom along if the atom it's bonded...

I have few questions trying to understand covalent bond in the simplest molecule H2 of two Hydrogen atoms. 1. Can covalent bond be created between two hydrogen atoms for which electrons have parallel spin? That is, electron in first hydrogen atom has spin UP and electron in the second hydrogen...

Homework Statement Homework Equations number of alpha hydrogens= number of no bond resonating structures The Attempt at a Solution option 1: 3 option 2: 6 option 3: 8 option 4: 9 So the answer should be 4, right?

Hey all, I am looking to make a simple atom and molecule simulator for a side project, I know it obviously has no hope of being 100% accurate due to my lack of degree in physics and processing power restrictions. So far I have made them bond according solely to valence rule (which I know its a...

Dear PF Forum, I'm trying to understand antioxidant and free radicals. But I'm afraid that my chemistry is weak. Perhaps someone can help me with this picture? https://en.wikipedia.org/wiki/Hydrogen_peroxide This is Hydrogen Peroxide. Neutral. As much as I can surmise in this picture is... 1...

Homework Statement Given that the bond energy of hydrogen-hydrogen bonds is 436 KJ/mol, that of hydrogen-oxygen bonds is 464 KJ/mol, and those in oxygen molecules 496 KJ/mol, what is the approximate heat of reaction for 2H2 + O2→2H2O Homework Equations Hproducts-Hreactants The Attempt at a...

Homework Statement Homework EquationsThe Attempt at a Solution 6C-H bonds= 410 x 6 = 2460 kJ/mol 3C-C bonds H of formation= +53.3 kJ/mol H of atomisation = +717 kJ/mol H-H = 436 kJ/mol as H of formation is 53.3, can't I just do: 2460+3x=53.3? But then I am not using a lot of the values...

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?

Recently, I read two chapters from March's advanced organic chemistry. I came across gauche effect and SN2 reactions. In both phenomena, ##\sigma-\sigma^*## orbital interactions is involved. In gauche effect present in 1,2-diflouroethane, the C-F bonding orbital becomes an antibonding orbital so...

I've read a few papers regarding the effects of a uniform magnetic field on water solutions, but I'm a complete illiterate when it comes to deciphering the jargon. So far, many papers confirm that a uniform magnetic field strengthens hydrogen bonds and can increase the redox potential. I've...

Homework Statement James bond is standing on a large frozen lake and fires his handgun horizontally. This exerts 1400N of force on the bullet over a distance of 10cm before leaving the barrel at 200m/s. What is the coefficient of kinetic friction between bond and the ice if he slid for 24.2 s...

From the resonance structures of Naphthalene, 1-2 Bond has more double Bond character than 2-3 Bond. In March's Advanced organic chemistry, its given that ozone preferentially reacts with 1-2 Bond. But the reaction is not given. Is this a normal ozonolysis reaction in which the 1-2 Bond is...

Homework Statement "By means of a balanced chemical equation, including state symbols, illustrate the term average C-H bond energy in methane." Ans: CH4 (g) -> C(g) + 4H(g) Average bond energy = +x/4 kj/mol Why C (g) ? Why is the state of C gas?

Here's the question: The structure of 1,3-butadiene is usually written as H2C=CH–CH=CH2. The average bond lengths given in Table 9.2 in my textbook are: C–C of 154 pm and C=C of 133 pm. Explain the fact that the observed value of the distance between the two central carbon atoms in...

Hydrogen sulphide has the same structure as water. The bonding in water is 104.5 degrees. As both have two bond pairs and two lone pairs of electron, shouldn't the bond angle in hydrogen sulphide be 104.5 degrees? Why is it 92 degrees? Is there anyway one can calculate the bond angles? Thanks.

How can you tell when a compound will form a covalent bond or a coordinate bond? I know that a coordinate bond is a special type of covalent bond and if during covalent bonding, if the elements taking part do not obtain a noble gas configuration, they for coordinate bonds. But take for example...

Taken from 'Concise Inorganic Chemistry - J.D.Lee': "According to Bent's rule, more electronegative atom not only prefers to stay in the orbital having more p-character but can also increase the p-character in its attached orbital of the central atom depending on the circumstance... With an...

How and why do isoelectronic species have the same bond order? My book cites an example that says that F2 and O2 -2 (oxygen molecule ion) has a bond order of 1. I understand how fluorine gas has a bond order of 1. But how does the oxygen molecule ion have a bond order of 1? Is it because they...

Why/How does Carbon's 3rd p-orbital contribute to its bond -- sp3 -- if it's vacant?

I was drinking a bottle of tea the other day, and I noticed the cap had a claim that two metals of the same type will stick together in space. Why is this? Edit: "Why" do metals...

Dear PF Forum, I know that this question is purely speculative. And I should have googled it, but... In James Bond film, "Day Another Day", we saw that the villain, portrayed by Toby Stephens tries (and I might say, succeeds) to tranfer energy from the sun to some spot on earth, whether it can...

http://www.iflscience.com/space/molecules-have-been-built-using-laser-beam-first-time Is there a way that fusion could be achieved with coherent control like this? If it can build molecules couldn't deuterium-deuterium be achieved?

My notes states that fluorine is too highly electronegative and hence clings on too tightly to its lone pair of electrons and so it cannot accept hydrogen bonds as well. However, it also stated that a hydrogen bond will be stronger if the electron density on the electron rich atom the stronger...

In my textbook one of the conditions for formation of ionic bond is given as The cation should be large and anion should be small But in the image of Nacl lattice structure ,we can see that it is other way around I am not getting the reason,Is my textbook wrong ? Or it has something to do with...

According to my textbook The distance at which attractive fOrces overcome repulsive forces is called bond distance. I want to ask if I would say The distance at which repulsive forces overcome attractive forces is called bond distance Will it be correct?

Hi guys, which of nh3 and N(CH3)3 have the smallest bond angle? My answer is NH3, because H is smaller than CH3. so lone pair electron of N can easily push the H and make the bond smaller. Is this right?

Hey guys, So, I was in my materials lecture today and something the lecturers and the tutors said was slightly confusing. We were talking about the repulsion and attraction force between atoms. This is all good as I can understand how if two atoms will repel each other if they get really close...

Hello, I am currently taking Organic Chemistry and was wondering what is the relationship between bond length, hybridization, and resonance? In other words, do some hybridization have smaller bond length? How is that affected by resonance?

Homework Statement Determine the hybridization of the atoms labeled A, B and C in the molecule and the bond angles around them. Homework Equations N/A 3. The Attempt at a Solution A. Normally, I would say it is sp3 for oxygen since there are 4 groups attached to it including the lone...

Homework Statement In a DNA molecule, the base pair adenine and thymine is held together by two hydrogen bonds (see figure below). Let's model one of these hydrogen bonds as four point charges arranged along a straight line. Using the information in the figure below, calculate the...

Strongest bond in chemistry ionic ,covalent or metallic?Bond strength decrease in the following order covalent > ionic > metallic so i think strongest bond would be covalent bonding then comes ionic bonding and at last metallic bonding.Correct me if i am wrong.One more question is water/ice...

It is my understanding that metals are a crystal lattice of ions, held together by delocalized electrons, which move freely through the lattice (and conduct electricity, heat, etc.). If two pieces of the same metal are touched together, why don't they bond? It seems to me the delocalized...

More acidity means more electronegativity, and more electronegativity means more dipole moments. I observed that liquids with low dipole moments (bases) often have lower density and surface tension, but not necessarily hydrogen bonds. To contradict it, acetic acid have a low surface tension but...

If you increase the surface tension of a liquid, does it change the average bond strength of the liquid?

How do you strengthen and weaken hydrogen bonds in water aside from changing its temperature? Could you add any solutes to do so?

Hi all- I am trying to make a semi-waterproof poster (only needs to be wet for a few hours and not necessary for the poster to last beyond the day) I need to back the poster on a hard surface - have tried correx but it won't accept any titebond glue as it is basically treated to be resistant...