Search found 51 matches
- Sat Dec 07, 2019 12:32 am
- Forum: Lewis Acids & Bases
- Topic: Stronger Base and Stronger Acid
- Replies: 3
- Views: 249
Re: Stronger Base and Stronger Acid
You can determine which acid is stronger by Bond Length and anion stability. The longer the bond length, the stronger the acid. The more stable a molecule is the stronger the acid. Oxoacids work a little differently: the more Oxygens, the higher the electronegativity of the central atom, and the hig...
- Sat Dec 07, 2019 12:26 am
- Forum: Naming
- Topic: writing formula of a given name
- Replies: 5
- Views: 385
Re: writing formula of a given name
It doesn't matter which way you write it, though you can write it from positive to neutral to negative charge. And if you encounter 2 atoms of the same charge then you can go by alphabetical.
Good to know: Metals are always put first when going from name to formula
Good to know: Metals are always put first when going from name to formula
- Sat Dec 07, 2019 12:21 am
- Forum: Polyprotic Acids & Bases
- Topic: Definition of Polyprotic
- Replies: 5
- Views: 589
Re: Definition of Polyprotic
A polyprotic acid can donate more than one proton, while a polyprotic base can accept more than one proton. Also, a good thing to know about polyprotic acids is that the acid becomes weaker after each proton it donates. For example, H2SO4 + H2O -> HSO4- + H3O+ and HSO4- + H2O -> SO4(-2) + H3O+ H2SO4...
- Sat Dec 07, 2019 12:16 am
- Forum: Bronsted Acids & Bases
- Topic: Strong vs. Weak
- Replies: 2
- Views: 241
Re: Strong vs. Weak
No, bond lengths are what determine strong acids (long) and weak acids (short). Also the rule that it'll be weak if it has an extra H won't suffice because H2SO4 dissociates to HSO4- and it is still a strong acid. A weak acid is usually organic compounds whihc have C and H.
- Sat Dec 07, 2019 12:12 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: EDTA
- Replies: 3
- Views: 314
Re: EDTA
It is a chelating ligand which binds 6 times thus it is a hexadentate
- Sun Dec 01, 2019 11:05 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Strong vs Weak Acids
- Replies: 7
- Views: 508
Re: Strong vs Weak Acids
Strong acids and bases are 100% ionized when reacted. Weak acids and bases are less than 100% ionized. Strong acids produce more protons than their weak counterpart while strong bases produce more hydroxide ions than weak bases.
- Sun Dec 01, 2019 10:49 am
- Forum: Conjugate Acids & Bases
- Topic: Conjugate acids
- Replies: 3
- Views: 261
Re: Conjugate acids
The conjigate acid is the molecule that gains a proton when a base is added into a solution Ex. NH3 + H20 -> NH4+ + OH- The rxn can be broken down like this, respectively: base + acid -> conjugate acid + conjugate base In this rxn H20 acts as an acid though it has a neutral pH. Water can act as an a...
- Sun Dec 01, 2019 10:18 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxidation number
- Replies: 3
- Views: 247
Re: Oxidation number
To find the oxidation number of a TM:
1) take the sum of all the oxidation numbers of each component bound to the central TM atom
2) find the overall charge of the molecule (usually given)
3) subtract the overall charge by the sum of all oxidation numbers stated in part 1
1) take the sum of all the oxidation numbers of each component bound to the central TM atom
2) find the overall charge of the molecule (usually given)
3) subtract the overall charge by the sum of all oxidation numbers stated in part 1
- Sun Dec 01, 2019 9:53 am
- Forum: Lewis Acids & Bases
- Topic: Lewis vs Bronsted
- Replies: 4
- Views: 294
Re: Lewis vs Bronsted
Yes because, for example, all Bronsted are Lewis but not all Lewis are Bronsted.
- Sun Dec 01, 2019 9:46 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number
- Replies: 2
- Views: 218
Re: Coordination Number
The coordination number of an atom in a molecule is the number of atoms bonded to the atom. For Cu+, it would simply be the possible amount of atoms that it could bond to. The coordination number represents the number of bonds the central atom has in a molecule. In regards to Cu+, the coord # would ...
- Sun Nov 24, 2019 8:52 pm
- Forum: Biological Examples
- Topic: Heme complex and biological significance
- Replies: 2
- Views: 226
Re: Heme complex and biological significance
Heme complex is the central atom iron that is bound to a ligand with a tetradentate structure (which binds to the iron is 4 different places) which binds to a protein structure and an oxygen molecule (O2). Its biological importance helps carry oxygen throughout the blood and cells.
- Sun Nov 24, 2019 8:45 pm
- Forum: Biological Examples
- Topic: Biological Significance
- Replies: 3
- Views: 256
Re: Biological Significance
The biological importance for transition metals surrounds the oxidation states of the TM for electron transfer. A few examples include
chromium: assists in control of blood sugar
iron: myoglobin, hemoglobin, e- transfer in the oxidation of carbohydrates, proteins, fats
chromium: assists in control of blood sugar
iron: myoglobin, hemoglobin, e- transfer in the oxidation of carbohydrates, proteins, fats
- Sun Nov 24, 2019 8:38 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Ligands
- Replies: 5
- Views: 330
Ligands
How do you find the oxidation state of transition metals in a coordination compound?
- Sun Nov 24, 2019 8:33 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis acids + bases and Bronsted acids + bases
- Replies: 6
- Views: 442
Re: Lewis acids + bases and Bronsted acids + bases
Bronsted refers to hydrogen donors (acid) and acceptors (base). Meanwhile, lewis refers to lone pair donors (base) and acceptors (acid).
- Sun Nov 24, 2019 8:29 pm
- Forum: Naming
- Topic: Meaning of Cis and Trans
- Replies: 11
- Views: 851
Re: Meaning of Cis and Trans
cis- means that the electronegative atoms are both on one side which creates a dipole moment. meanwhile trans- means that the electronegative atoms are on opposite sides whicgh the dipole moments cancel out, thus there is no dipole moment. In regards to cis/trans-platin, the chlorine atoms are the p...
- Wed Nov 13, 2019 4:28 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Similar terms
- Replies: 3
- Views: 257
Re: Similar terms
London Dispersion Forces (and van der Waals) are temporary attractive forces that occur when very slight opposing charges are adjacent for a brief amount of time to create short-lived dipoles. Induced dipole - induced dipoles can be referred to as LDF/van der Waals because of this.
- Wed Nov 13, 2019 4:10 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Boiling Point
- Replies: 6
- Views: 377
Re: Boiling Point
Concept: The stronger the bond, the higher the boiling point.
From highest to lowest boiling point:
ion - ion
ion - dipole
hydrogen bond
dipole - dipole
induced dipole - dipole
induced dipole - induced dipole
From highest to lowest boiling point:
ion - ion
ion - dipole
hydrogen bond
dipole - dipole
induced dipole - dipole
induced dipole - induced dipole
- Wed Nov 13, 2019 4:00 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Intermolecular Forces vs Bonding???
- Replies: 5
- Views: 394
Re: Intermolecular Forces vs Bonding???
Ion-dipole, LDF, and dipole-dipole, etc are intermolecular forces: forces between two different molecules meanwhile polar/nonpolar are intramolecular forces (within the molecule).
Also, dipole-dipole: interactions between 2 polar molecules
LDF: interactions between 2 non polar molecules
Also, dipole-dipole: interactions between 2 polar molecules
LDF: interactions between 2 non polar molecules
- Wed Nov 13, 2019 3:51 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Dipole-Dipole Moments
- Replies: 3
- Views: 239
Re: Dipole-Dipole Moments
The larger the molecule means a greater amount of electrons to be polarized, and therefore a stronger induced dipole-dipole moment?
Yes, the molecular size is proportional to the strength of the dipole moment. As one increases, so does the others.
Yes, the molecular size is proportional to the strength of the dipole moment. As one increases, so does the others.
- Wed Nov 13, 2019 3:49 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: H-bonding & Dipole-Dipole (Problem 3F.1)
- Replies: 4
- Views: 321
Re: H-bonding & Dipole-Dipole (Problem 3F.1)
Yes! Hydrogen bonding is a special form of dipole-dipole forces with hydrogen bonding exhibiting stronger intermolecular forces. This is because H (low EN) is paired with N,O, or F (high EN)
- Sun Nov 10, 2019 1:20 am
- Forum: Dipole Moments
- Topic: Hydrogen Bonds, Electronegativity
- Replies: 1
- Views: 148
Re: Hydrogen Bonds, Electronegativity
A Chlorine-Hydrogen bond cannot form hydrogen bonds because Cl has too large of a radius, thus creating an electron density not sufficient enough to form Hydrogen bonding.
- Sun Nov 10, 2019 1:15 am
- Forum: Electronegativity
- Topic: Electronegativity and hydrogen bonds (3F.11)
- Replies: 2
- Views: 411
Re: Electronegativity and hydrogen bonds (3F.11)
HNO2 is the only ones that will form Hydrogen bonds because there is a greater electronegativity difference between O and H thus making it polar / able to form H-bonds. In the case of Br, Br is too large to have enough electronegativity to pull the electrons more than the H can. H has to bind to a h...
- Sun Nov 10, 2019 1:09 am
- Forum: Bond Lengths & Energies
- Topic: Bond Lengths
- Replies: 8
- Views: 537
Re: Bond Lengths
Double bonds are shorter in length than single bonds because they are stronger and harder to break apart due to the atoms sharing more electrons and a greater attraction.
- Sun Nov 10, 2019 1:06 am
- Forum: Dipole Moments
- Topic: Polar
- Replies: 9
- Views: 524
Re: Polar
How do you know if a molecule is polar or not so you can state whether it is a dipole-dipole or london dispersion? A dipole-dipole interaction between molecules alludes that the molecule is polar while london dispersion forces alludes to the molecular interactions being non polar. An interaction, in...
- Sun Nov 10, 2019 1:01 am
- Forum: Sigma & Pi Bonds
- Topic: Triple bond?
- Replies: 18
- Views: 1655
Re: Triple bond?
A triple bond consists of one sigma bond and one pi bond
- Fri Nov 01, 2019 6:58 pm
- Forum: Sigma & Pi Bonds
- Topic: Difference between sigma and pi bonds
- Replies: 4
- Views: 261
Re: Difference between sigma and pi bonds
Sigma bonds are the initial bond between 2 atoms and as more bonds (double & triple bonds) form, each bond (except for one) is considered an added pi bond. for example, a double bond would be 1 sigma bond and 1 pi bond; and a triple bond would be 1 sigma bond and 2 pi bonds. sigma bonds are also...
- Fri Nov 01, 2019 6:53 pm
- Forum: Lewis Structures
- Topic: Expanded Valence Shells
- Replies: 4
- Views: 202
Re: Expanded Valence Shells
If an atom has an incomplete d and 3(+)p orbital(s) in period 3 and down, they can have an expanded valence shell. In the Lewis dot diagram, the number of electrons do not really go past 12, which fortunately helps for space & convenience's sake.
- Fri Nov 01, 2019 6:40 pm
- Forum: Octet Exceptions
- Topic: Octet Exception
- Replies: 3
- Views: 171
Re: Octet Exception
No, we don't have to memorize the octet exceptions. But it's good to know (not relating to "exceptions") that only atoms in row 2&3 maxes at 8 valence electrons because in row 4, for example, they have more space in their d block.
- Fri Nov 01, 2019 6:27 pm
- Forum: Electronegativity
- Topic: Electronegativity vs. Electron Affinity
- Replies: 7
- Views: 286
Re: Electronegativity vs. Electron Affinity
Electronegativity is the tendency to gain an electron meanwhile electron affinity is the energy released when an electron is transferred to an anion
- Fri Nov 01, 2019 6:24 pm
- Forum: Octet Exceptions
- Topic: More than 8 valence e-
- Replies: 8
- Views: 356
Re: More than 8 valence e-
Only the 2nd row in the periodic table can have a maximum of 8 valence electrons because it has the 2s and 2p orbitals
- Wed Oct 23, 2019 2:11 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs covalent
- Replies: 8
- Views: 845
Re: Ionic vs covalent
In a simpler observation (not including any calculations), ionic bonds are bonds between a metal and nonmetal where electrons are donated/transferred. Meanwhile, covalent bonds are bonds between 2 non-metals where electrons are shared. Ionic bonds also tend to have a high boiling point and a large p...
- Wed Oct 23, 2019 2:04 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs Covalent
- Replies: 32
- Views: 43267
Re: Ionic vs Covalent
In natural life, covalent bonds are stronger than ionic bonds due to the natural aqueous state that surrounds us. Because ionic bonds become weak when placed in water/polar-aqueous solution. In a theoretical "dry/non-aqueous" world, ionic bonds are stronger than covalent bonds. In other wo...
- Wed Oct 23, 2019 2:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: Back and Fourth Arrows
- Replies: 6
- Views: 746
Re: Back and Fourth Arrows
Double headed arrows is the symbol that implies that the reaction is reversible. If an arrow is pointing only one way then that implies that the reaction is nonreversible.
- Wed Oct 23, 2019 1:59 pm
- Forum: Ionic & Covalent Bonds
- Topic: Xenon -- why is it the only noble gas that can form bonds?
- Replies: 4
- Views: 4430
Re: Xenon -- why is it the only noble gas that can form bonds?
Xe can form bonds because it has a very large atomic radius compared to other noble gases meaning that the ionization energy of the atom for the outermost electrons is relatively minimal, minimal enough to allow it to create bonds with atoms that have relatively high electronegativity.
- Wed Oct 23, 2019 1:55 pm
- Forum: Ionic & Covalent Bonds
- Topic: Difference Between Ionic and Covalent
- Replies: 8
- Views: 1001
Re: Difference Between Ionic and Covalent
Ionic bonds are bonds between a metal (cation) and a nonmetal (anion) and the cation donates the electron to the anion because of the large difference in electronegativity and ionization energy. Meanwhile, covalent bonds are between two nonmetals and they share the electron(s) by the electron transf...
- Fri Oct 18, 2019 11:32 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Best Way To Study?
- Replies: 56
- Views: 3346
Re: Best Way To Study?
It tends to depend on personal preferences and through trying different strategies to see which one clicks the most. Personally, what really helps me is going over youtube videos/his modules and doing many practice problems to get the routines down and know when to use which formula depending on wha...
- Fri Oct 18, 2019 11:27 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: heisenberg, calculating kinetic energy
- Replies: 3
- Views: 171
Re: heisenberg, calculating kinetic energy
I think it isn't working because there is a small error in your formula.
The equation for kinetic energy: KE = (0.5)*mass*velocity^2.
Also, another equation you will need later on: ΔxΔp >= h/(4pi)
The equation for kinetic energy: KE = (0.5)*mass*velocity^2.
Also, another equation you will need later on: ΔxΔp >= h/(4pi)
- Fri Oct 18, 2019 11:17 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Why divide h by 4pi?
- Replies: 5
- Views: 329
Re: Why divide h by 4pi?
Scientists found out that 4pi is a constant that is consistent whenever using the formula. If you want a more specific answer, Dr. Lavelle said that to discover this we have to fully understand the derivation of the equation which is a long and tedious process since most of the information we haven'...
- Fri Oct 18, 2019 11:08 am
- Forum: DeBroglie Equation
- Topic: 1B.15a
- Replies: 2
- Views: 186
Re: 1B.15a
During my discussion, the TA said that for anything that has mass (like electrons), we should use the equation: wavlength = h/(mv)
Meanwhile, anything that doesn't have mass (like photons), we use the equation: wavelength = c/(frequency)
mass of electron = 9.11 * 10^-31 kg
Meanwhile, anything that doesn't have mass (like photons), we use the equation: wavelength = c/(frequency)
mass of electron = 9.11 * 10^-31 kg
- Fri Oct 18, 2019 10:59 am
- Forum: DeBroglie Equation
- Topic: Energy = mv^2
- Replies: 2
- Views: 141
Re: Energy = mv^2
Dr. Lavelle generalized the concept so I wouldn't use that equation since there are more complicated and accurate ways to achieve the derivation. He said to not worry about it too much since it won't be a main focal point in the midterms and finals.
- Tue Oct 08, 2019 4:23 pm
- Forum: Properties of Electrons
- Topic: Energy of an Electron
- Replies: 2
- Views: 589
Re: Energy of an Electron
The energy of a photon = (planck's constant) * (speed of light) / wavelength
I think this is probably the closest that you can get to what you are looking for.
I think this is probably the closest that you can get to what you are looking for.
- Tue Oct 08, 2019 4:19 pm
- Forum: Photoelectric Effect
- Topic: Post Assessment Problem 28
- Replies: 2
- Views: 270
Re: Post Assessment Problem 28
For anyone else wondering, the mass of an electron is about 9.11 × 10^(-28) grams.
- Tue Oct 08, 2019 4:15 pm
- Forum: Properties of Light
- Topic: Wave and Photon Models
- Replies: 2
- Views: 145
Wave and Photon Models
How can we determine if the problem is asking for a wave model or a photon model?
- Tue Oct 08, 2019 4:07 pm
- Forum: Properties of Electrons
- Topic: Electron Gaining/Losing energy
- Replies: 5
- Views: 648
Re: Electron Gaining/Losing energy
When atoms absorb energy, the electrons go into an "excited" state which moves them up electron orbitals. In short, when an atom is excited, electrons have absorbed energy.
- Tue Oct 08, 2019 4:04 pm
- Forum: Einstein Equation
- Topic: Planck's constant
- Replies: 9
- Views: 603
Re: Planck's constant
Planck's constant is critical as a constant because it relates the energy of a photon to its frequency.
- Fri Oct 04, 2019 12:06 am
- Forum: Properties of Light
- Topic: Spectroscopy
- Replies: 4
- Views: 190
Re: Spectroscopy
There is an acronym for visible light from longest to shortest wavelength is ROY-G-BIV (red, orange, yellow, green, blue, indigo, violent). I don't know any acronyms for the rest but the general graph/chart from shortest to longest is: gamma rays, x-rays, ultraviolet, visible light (ROY-G-BIV backwa...
- Wed Oct 02, 2019 4:32 pm
- Forum: Properties of Electrons
- Topic: Polar vs Non polar
- Replies: 15
- Views: 4560
Re: Polar vs Non polar
A polar molecule is when there are slight positive and/or negative charges within the atoms. This is formed when one of the atoms tends to attract the electrons more than the others due their electronegativity levels. Hydrogen and Carbon tend to have low electronegativity levels that is why all hydr...
- Wed Oct 02, 2019 4:20 pm
- Forum: Properties of Light
- Topic: Electric Field and Magnetic Field
- Replies: 3
- Views: 183
Electric Field and Magnetic Field
What is the difference between the electric and magnetic fields? In other words, what are the electric and magnetic fields and what role does each of them play?
- Wed Oct 02, 2019 4:12 pm
- Forum: Balancing Chemical Reactions
- Topic: Equations Balancing
- Replies: 6
- Views: 397
Re: Equations Balancing
I use variables to associate all of the coefficient together with. Usually, I assign the most complex compound the variable 'x' then I go step by step linking the other molecules to 'x'. And then I assign them the coefficient that all the different molecules had for 'x'. And for what is left (or doe...
- Wed Oct 02, 2019 3:55 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2996371
Re: Post All Chemistry Jokes Here
Oxygen, Hydrogen, Sulfur, Sodium, and Phosphorus walk into a bar.
The bartender exclaims "OH SNaP!"
The bartender exclaims "OH SNaP!"
- Wed Oct 02, 2019 3:35 pm
- Forum: SI Units, Unit Conversions
- Topic: Question about Showing Work
- Replies: 22
- Views: 995
Re: Question about Showing Work
It's always better to show work than not because you can earn at least partial credit even though you may have got the answer wrong by making an incorrect step/calculation.