Dear CH304,
Predict with suitable explanation which compound has stronger inter-atomic bond, BeBr2 or AlBr3?
Answer
BeBr2 and AlBr3 covalent compounds. If both were ionic compound, both compound contains a very small and highly charge cation and a large anion. This results in the cation to polarise the anion's electron cloud, hence making electron clouds to overlap.
Since both BeBr2 and AlBr3 are covalent compounds, Be is a smaller atom than Al. Hence, the extent of overlapping of atomic orbital between Be and Br is greater than in Al and Br. Hence, Be-Br single bond is stronger than in Al-Br single bond.
Comments
The most comprehensive answer goes to Xing Ting, Johanan, Wei Jie and Dung. =)
The following are the misconceptions made. I have included the names so that we can all learn from each other. I think it wld be excellent if you would like to take this question into further discussion.
1. Stating that BeBr2 and AlBr3 are dative covalent compounds. Please don't say that. Covalent compound is good enough. - Eileen's answer
2. Not applying to the definition of covalent bond (key words missing out) completely. - Eileen's, Jo's, Daniel's
3. Thinking that BeBr2 are AlBr3 ionic compounds - Xiao Min's, Lyria
4. Incomplete sentence expression (with ambiguous word(s)). - Sherlyn (what is it?), Jing Yew (Am i going to assume that you meant covalent bonds are formed?)
5. Totally missing the point. Thinking that I am trying to account for dative bond or why covalent bond, when I am actually trying to determine strength of bond. - Peck Fen, Wen Han, Brandon
6. Writing irrelevant information (e.g. "Bond pair replusion", "more bonds bonds formed around Al, does not mean the bond is stronger", "VSEPR" and "Charges of Be and Al") - Renaldy, Benjamin, Crystal, Kevin, Nicholas
7. Trying to answer too much. Uses both definition of covalent bonding. (can get abit confusing). - Samuel
Predict with suitable explanation which compound has stronger inter-atomic bond, BeBr2 or AlBr3?
Answer
BeBr2 and AlBr3 covalent compounds. If both were ionic compound, both compound contains a very small and highly charge cation and a large anion. This results in the cation to polarise the anion's electron cloud, hence making electron clouds to overlap.
Since both BeBr2 and AlBr3 are covalent compounds, Be is a smaller atom than Al. Hence, the extent of overlapping of atomic orbital between Be and Br is greater than in Al and Br. Hence, Be-Br single bond is stronger than in Al-Br single bond.
Comments
The most comprehensive answer goes to Xing Ting, Johanan, Wei Jie and Dung. =)
The following are the misconceptions made. I have included the names so that we can all learn from each other. I think it wld be excellent if you would like to take this question into further discussion.
1. Stating that BeBr2 and AlBr3 are dative covalent compounds. Please don't say that. Covalent compound is good enough. - Eileen's answer
2. Not applying to the definition of covalent bond (key words missing out) completely. - Eileen's, Jo's, Daniel's
3. Thinking that BeBr2 are AlBr3 ionic compounds - Xiao Min's, Lyria
4. Incomplete sentence expression (with ambiguous word(s)). - Sherlyn (what is it?), Jing Yew (Am i going to assume that you meant covalent bonds are formed?)
5. Totally missing the point. Thinking that I am trying to account for dative bond or why covalent bond, when I am actually trying to determine strength of bond. - Peck Fen, Wen Han, Brandon
6. Writing irrelevant information (e.g. "Bond pair replusion", "more bonds bonds formed around Al, does not mean the bond is stronger", "VSEPR" and "Charges of Be and Al") - Renaldy, Benjamin, Crystal, Kevin, Nicholas
7. Trying to answer too much. Uses both definition of covalent bonding. (can get abit confusing). - Samuel
I am basing my answer on "stronger inter-atomic bond" instead of intra-atomic bond because intra-atomic bonding is bonding WITHIN an atom, which we haven't learnt yet. I hope it's not a trick question of sorts...
ReplyDeleteThe bonding in BeBr2 is most likely covalent because Be2+ ion is a relatively small particle with +2 charge (charge density high). While Br- has large electron cloud (highly polarisable). This means Be2+ will distort the electron cloud of Br- and make the orbitals of both ions overlap. A covalent bond is formed.
The bonding in AlBr3 is most likely covalent because Al3+ ion is still a small particle with +3 charge (charge density high). While Br- has large electron cloud (highly polarisable). This means Al3+ will distort the electron cloud of Br- and make the orbitals of both ions overlap. A covalent bond is formed.
Because Be2+ is smaller than Al3+. The shared electrons in BeBr2 are much closer to the nuclei of the atoms than AlBr3. They experience more electrostatic attraction in BeBr2 than AlBr3. Thus the overlapping of orbitals is much more effective in BeBr2 than AlBr3, more energy is needed to break the bond in BeBr2 than AlBr3, so the bond is stonger in BeBr2.
Based on the VSEPR theory, there exists bond pair-bond pair repulsion in covalent molecules. In BeBr2, the molecule geometry exists in a linear form where the bond pairs are located at 180ยบ to each other compared to AlBr3 where its molecular geometry is that of trigonal planar in which the bond pairs are placed at 120° to each other. As such, the intra-atomic bonds in AlBr3 are weaker compared to those in BeBr2 due to the smaller bond angles present, thus resulting in more repulsion amongst the atoms in AlBr3.
ReplyDeleteAnother reason is that the Al atom is considerably larger than an atom of beryllium, resulting in a less effective overlapping of atomic orbitals due to a larger atomic radius compared to that in beryllium. Sincr both covalent compounds consist of bromine, thus the atom with a smaller atomic radius would have a larger percentage of the overlapping of atomic orbitals, therefore causing the intra-atomic bonding in BeBr2 to be stronger than that in AlBr3.
Both BeBr2 and AlBr3 are covalent compound. This is because the metal atoms (Be and Al) are so highly positively charged that they attract the electron cloud around the non-metal atoms (Br), overlapping of electron orbitals occur, hence covalent bonds formed.
ReplyDeleteThe bond formed between Br and Be is stronger than the bond formed between Br and Al. This is because Be has a smaller atomic size compared to Al. Hence, the extent of overlapping of atomic orbitals between Be and Br atoms is greater than that between Al and Br atoms. The greater the extent of overlapping, the stronger the bond formed since the electrons are closer to the nuclei -> stronger forces of attraction.
The Be-Br bond is stronger than the Al-Br bond.
ReplyDeleteThe Be atom is smaller than the Al atom. Therefore, the overlapping of the electron orbital between Be and Br is more effective than that of Al and Br. This results in the Be-Br bond being stronger than the Al-Br bond, thus the intra-molecular bonds of BeBr2 are stronger.
-Timothy Kwok
BeBr2 will have stronger intra-atomic bonds.
ReplyDeleteThis is so because Be atom has a smaller atomic size as compared to Al atom. As such, overlappings of atomic orbitals of Be and Br are more effective than those of Al and Br. Hence, BeBr2 has stronger covalent bonds than AlBr3, despite having lesser number of bonds.
Both BeBr2 and AlBr3 are bonded covalently within the molecule.
ReplyDeleteSince strength of covalent bond is affected by 2 factors namely the size of the atoms involved, and the number of bonding electrons, and in this case both compounds have the central atom of Be and Al having the same number of bonding electron of 1, therefore we only consider the size of the atom.
Be lies in the 2nd period of the periodic table thus only having 2 principle quantam shells. On the other hand, Al lies in the 3rd period of the periodic table and hence has 3 quantam shells.
Since the size of Be is smaller than Al,the distance between shared electrons and the nuclei of Be Br is smaller as compared to the distance between shared electrons and the nuclei of Al and Br, hence there will be a larger extent of overlapping between the atomic orbitals resulting in a stronger covalent bond.
The other explanation could be that since the atomic radius of Be is smaller as compared to Al, when bonded covalently with Br, the electrostatic attraction between the shared electrons and the nuclei of the Be and Br is stronger than the electrostatic attraction between the shared electrons and the nuclei of the Al and Br. Therefore, this leads to a larger extent of overlapping orbitals in the compound of BeBr2, resulting in a stronger bond.
My guess would be...
ReplyDeleteBeBr2 has the stronger intra-atomic bond.
Firstly, we shall establish that both compounds have the same type of intra-atomic bond, covalent bonds. Covalent bonds are formed by the sharing of electrons between atoms. Hence, theoretically, the strength of the intra-atomic bonds of the compounds should be equal.
Next, looking at the number of bonding electrons, we find that there is a single pair of bonding electrons between Be and each Br in BeBr2 .Similarly, there is a single pair of bonding electrons between Al and each Br in AlBr3. Hence, from the perspective of the number of bonding electrons, the electrostatic forces of attraction between the atoms in the respective compounds would be equally strong.
However, Be, as the smaller atom, has a smaller atomic orbital as compared with Al. Hence, there would be a greater extent of effective overlapping of atomic orbitals between Be and Br as compared with that between Al and Br. This results in a stronger covalent bond between Be and Br as compared with Al and Br.
Hence, from the perspective of atomic size, BeBr2 has a stronger intra-atomic bond as compared with AlBr3.
Overall, this results in BeBr2 having the stronger intra-atomic bond of the two compounds.
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Regards,
Chia Wei Jie
Answer: BeBr2 has a stronger intra-atomic bond, compared to AlBr3.This is probably because firstly, the central atom in BeBr2 (beryllium) is smaller than Aluminium in alBr3.Thus, the extent of overlapping between the atomic orbitals is larger,resulting in a stronger atomic bond.Also,the polarity difference between Be and Br is larger than Al and Br,thus, the partial charges in BeBr2 are stronger than in Albr3.This gives rise to a stronger covalent bond.
ReplyDeleteBeBr2 and AlBr3 are both covalent compounds that are formed due to the high charge density cation of Be and Al, as well as the large anion of Br. Thus, the cations are highly polarizing while the anion is highly polarizable. As a result, when the electron cloud of Al overlap with Br, it results in the two atoms sharing electrons, forming a covalent bond. The same goes for Be and Br.
ReplyDeleteThe BeBr2 exists as a chain of monomers. Each be atom is bonded to two other Br atoms by dative covalent bonds, thus forming an octet structure
The AlBr3 exists as a dimmer. As the Al atom has an extra orbital and the Br has lone pairs of electrons, the Al of one AlBr3 compound forms dative covalent bonds with the Br of another Albr3 compound and vice versa.
As the Be has a smaller electron size than Al, it has a larger extent of overlapping between atomic orbital with Br. Thus, it has stronger dative covalent bonds.
Also, there are more electrons in BeBr2 molecules participating in bonding (dative covalent bonding) than in a molecule of AlBr3. therefore, BeBr2 experience a stronger electrostatic forces of attraction, leading to stronger covalent bonds formed.
Both BeBr2 and AlBr3 are covalently bonded. Although the compound consists of a non metal and a metal, covalent bonding exists instead of ionic bonding because the cations are small in size yet carry a high charge. Thus, the cations have a high polarising power that can polarise the electron clouds of Bromine causing the overlapping of electron clouds charasteristic of covalent bonding.
ReplyDeleteSince covalent bonds are formed when the orbitals of two atoms overlap, a stronger covalent bond is formed when there is a greater degree of overlap of the orbitals. Beryllium being the smaller element would therefore have a greater degree of overlap of its orbital with bromine compared to the aluminium-bromine overlap. Hence, stronger inter-atomic bonds would exist between BeBr2 than AlBr3
AlBr3 will have the stronger intra-atomic bond.
ReplyDeleteAl has a charge of 3+ compared to Be which has a charge of 2+. This means that the Al3+ ion will attract the bonding pair of electrons more strongly than the Be2+ ion. Therefore, the electrons are closer to Al in AlBr3 as compared to Be in BeBr2. As a result the slight negative charge on Al is stronger than the slight negative charge on Be. The slight positive charge on Br in AlBr3 is also stronger than the slight positive charge on Br in BeBr2. Therefore, the Al and Br atoms attract each other more strongly than the Be and Br atoms.
Be is smaller than Al, which means that the bonding pair of electrons are closer to Be as compared to Al. However, this only involves Be and the electrons. The attraction between the slightly negative Al and the slightly positive Br is more significant in this case, as it involves attraction between the two atoms involved in the bond. For attraction between Be and the bonding pair of electrons, it does not involve Br. Hence, AlBr3 has stronger Intra-atomic bonds than BeBr2.
Both BeBr2 and AlBr3 form covalent bonds.
ReplyDeleteAl is a small atom with a large charge. Thus having a high charge density.
Despite being of lower charge, Be has a smaller ionic radius, thus it would also have a high charge density. On the other hand, barium is a large cation, thus being easily polarized.
However, when the covalent bond is formed in BeBr2, the central atom of Be is electron deficient and would form dative covalent bonds with other BeBr2 molecules. This is possible as the Br atoms would have more than one lone pair which can contribute to this dative bond. Due to the fact that the central atom of BeBr2 would only have 4 electrons, it would thus need to form 2 dative covalent bonds with its surrounding molecules.
AlBr3 would also have a central atom of Al being electron deficient, needing the Br atom of other AlBr3 molecules to contribute a lone pair of electrons. As the Al atom would have 6 electrons after forming covalent bonds, it would form 1 dative covalent bond.
Therefore, BeBr2 would have stronger intra atomic bonds than AlBr3 as one of the molecules would form 2 dative covalent bonds while AlBr3 would only form one.
This is evident from the higher boiling point of BeBr2 at 520 degrees Celsius while AlBr3’s is at 255 degrees Celsius
BeBr2 has a stronger intra-atomic bond. Both compounds, BeBr2 and AlBr3 are covalent compounds, and the strength of covalent bond is determined by the size of atom and the number of bonding electrons. In this case, the covalent bonds between Be and Br and the bonds between Al and Br are all single covalent bonds, therefore they are of the same strength. However, because Be has a smaller atomic size than Al, the extent of overlapping between atomic orbitals of Be and Br is larger than the extent of overlapping between atomic orbitals of Al and Br, therefore the BeBr2 compound has stronger intra-atomic bond.
ReplyDeleteBe atom is found in Period 2, while Al atom is found in Period 3. Hence, Be atom is smaller than Al atom. There is a shorter distance between the nucleus and electrons of Be atom, hence, there is a stronger electrostatic attraction between the electrons and the nucleus of Be atom compared to Al atom. The intra-atomic bond is stronger in BeBr2 compared to AlBr3.
ReplyDeleteThe intra-molecular bond is also stronger in BeBr2 because Be atoms are smaller than Al atoms. Be atomic orbitals are smaller than Al atomic orbitals. There is a more effective overlapping of atomic orbitals between Be and Br atoms compared to Al and Br atoms. Hence, the intra-molecular bond formed in BeBr2 is stronger than AlBr3.
It will be BeBr2 since it has less bonding pair hence it will have less repulsion between the pair of electrons, also, Be is a smaller atom compared to Al since it is located in period 2, that means the electrons being shared is located closer to the nucles compared to the bonding pair at AlBr3. hence the attractive forces from the nucleus would make the bond at BeBr2 stronger than the ones at AlBr3
ReplyDeleteAlBr3 will have stronger intra-atomic bonds than BeBr2.
ReplyDeleteThe bonds between Al and Br and Be and Br are ionic bonds. The ionic bonds between the positively charged Al and the negatively charged Br in AlBr3 will be stronger than the ionic bonds between the +ve Be and -ve Br because the strength of ionic bonds in an ionic compound is proportional to [(magnitude of charge on cation x magnitude of charge on anion) / (atomic radius of cation + atomic radius of anion) ]
Let [(magnitude of charge on cation x magnitude of charge on anion) / (atomic radius of cation + atomic radius of anion) ] be known as r and the atomic radius of Br anion be m.
For AlBr3, r is 3/atomic radius of Al cation + m)whereas for BeBr2, r is 2/atomic radius of Be cation + m).
The atomic radius of Be cation is 0.490 whereas the atomic radius of Al cation is 0.510. There is a negligible difference in atomic radii (0.02). Thus the value of r for AlBr3 is larger than that of BeBr2, and the intra-atomic bonds in AlBr3 are stronger.
BeBr2 has a stronger intramolecular bond than AlBr3. The Be atom is much more diminuitive than the Al atom. Thus, the overlapping of electron orbitals between Be and Br is much more effective than the overlapping of electron orbitals between Al and Br. This results in the Be-Br bond being stronger than the Al-Br bond hence the intermolecular bonds of BeBr2 is stronger.
ReplyDeleteBeBr2 is stronger.
ReplyDeleteAs Be has a smaller atomic size compared to Al, the extent if overlapping of orbitals is larger. Hence the interatomic bonds in BeBr2 are stronger than AlBr3.
-Abbie
BeBr2 is a stronger compound. AlBr3 forms a dimer with a Br on each AlBr3 donating a lone pair of electrons to the Al of the other AlBr3. However, because Be has only 2 valence electrons, it can accept 2 more lone pairs. 2 Br donate a lone pair each to another Be, and the 2 Br on this Be donates a lone pair each to another Be, forming a polymer, which is much stronger than the dimer as seen in AlCl3.
ReplyDelete1 Be atom share a pair of electrons with each Br atom, forming single covalent bonds with 2 Br atoms. Hence, the Be atom can still accept 4 more electrons to fill up its orbitals/achieve the octet electron configuration. On the other hand, the Br atoms will each have 3 lone pairs of electrons. Hence, while sharing a pair of electron with 1 Be atom, each Br atom will contribute a lone pair of electrons to another Be atom by forming a dative covalent bond. Thus, each Be atom will form 2 dative covalent bonds with 2 Br atoms and 2 single covalent bonds with another 2 Br atoms. Since it is a polymer, the intra-atomic bond is stronger.
ReplyDeleteThe AlBr3 on the other hand share 3 single covalent bonds with 3 Br atoms and 1 dative covalent bond with another Br atom bonded to the other Al atom, forming a dimer of AlCl6 when cooled below 400 degree Celsius. AlBr3 cannot form a polymer because Al can only accept 1 lone pair of electrons after forming 3 single covalent bonds with 3 Br atoms. It does not have enough empty orbitals to accept another lone pair of electrons.
Both BeBr2 and AlBr3 are molecules with covalent bonds, because they share the cloud of electrons due to their uneven electroneativity. Also, for BeBr2, Be usually form covalent bonds with non-metals, despite it being a metal because it is very small and has very high surface charge density. Forming ionic bonds would require too much energy.
ReplyDeleteFor covalent bonds, a compound with stronger intra-atomic bond would be one with a greater extent of overlapping of orbitals. Therefore, BeBr2 has stronger intra-atomic bond because it is much smaller in comparison with Al thus it'll have a more effective overlapping of orbitals with Br.
BeBr2
ReplyDeleteBe is in period 2 while Al is in period 3. From this, we know that Be has a smaller atomic radius. This would mean that the the nuclei's of Be and Br atoms would be nearer to each other compared to Al and Br.
BeBr2 has a stronger intra-atomic bond than AlBr3. This is due to the fact that Be is a smaller ion than Al. Hence, it has a smaller inter-ionic compared to Al. Thus, it has a greater magnitude of lattice energy than Al, causing BeBr2 to have a stronger intra-atomic bond.
ReplyDeleteHi Mr Kwok, I'm not sure if you're referring to inter-atomic bond instead of intra-atomic bond? If there's no error I apologise if I'm not answering the question properly.
ReplyDeleteBeBr2 has stronger inter-atomic bond. Both BeBr2 and AlBr3 are covalent compounds, bonded together by electrostatic forces of attraction between their nuclei and the shared electrons.
The Be atom is smaller than the Al atom, thus the distance between the shared electrons in BeBr2 is smaller as compared to that in AlBr3. As a result, the bond between atoms (inter-atomic bond) in BeBr2 is stronger than that in AlCl3.
Both BeBr2 and AlBr3 are dative covalent bonds, and both of which have one bonding pair of electrons per covalent bond. BeBr2 has a stronger inter-atomic bond due to the smaller atomic size of Be compared to Al, so the distance between the nuclei of Be and Br is smaller than the distance between the nuclei of Al and Br, resulting in the greater and more effective overlap between the atomic orbitals, and so the covalent bond is stronger in BeBr2.
ReplyDelete