Search found 51 matches
- Sun Dec 08, 2019 5:00 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: melting point
- Replies: 4
- Views: 394
Re: melting point
Molecules with a higher melting point would have stronger intermolecular forces. If the molecules you are comparing have the same IMF's, you would then look at the atom size. Bigger atoms would have a higher melting point because they are more polarizable, which creates greater attractive forces, ma...
- Sun Dec 08, 2019 4:55 pm
- Forum: Lewis Acids & Bases
- Topic: Mg(OH)2 Considered strong or weak base?
- Replies: 5
- Views: 3261
Re: Mg(OH)2 Considered strong or weak base?
Mg(OH)2 is a strong base because hydroxides in Groups 1 and 2 in the Periodic table are considered strong bases.
- Sun Dec 08, 2019 4:52 pm
- Forum: Industrial Examples
- Topic: Chemotherapy
- Replies: 22
- Views: 1709
Re: Chemotherapy
Cisplatin is a chemotherapy drug that binds to DNA by substituting Cl for two adjacent Guanines. It blocks cell division (replication), which treats cancer.
- Sun Dec 08, 2019 4:49 pm
- Forum: Naming
- Topic: bis- tris- tetrakis-
- Replies: 8
- Views: 632
Re: bis- tris- tetrakis-
These prefixes would be used for polydentates.
- Sun Dec 08, 2019 4:48 pm
- Forum: Resonance Structures
- Topic: Molecules with resonance
- Replies: 4
- Views: 510
Re: Molecules with resonance
Acids with resonance are stronger because resonance stabilizes the anion by withdrawing electron density and spreading out the charge.
- Sun Dec 08, 2019 4:45 pm
- Forum: Dipole Moments
- Topic: Hydrogen bonding AND Dipole-Dipole?
- Replies: 3
- Views: 379
Re: Hydrogen bonding AND Dipole-Dipole?
Although it is redundant, it is still best to indicate that there are both hydrogen bonds and dipole-dipole forces.
- Sun Dec 01, 2019 1:26 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Difference between Arrhenius, Bronsted, and Lewis
- Replies: 5
- Views: 9156
Re: Difference between Arrhenius, Bronsted, and Lewis
An Arrhenius acid is a molecule that donates an H+ ion when dissolved in water, so it is a proton donor. An Arrhenius base is a molecule that yields an OH- ion when dissolved in water. Bronsted-Lowry acids are proton donors, and Bronsted-Lowry bases are proton acceptors. Lewis acids are electron pai...
- Sun Dec 01, 2019 1:16 am
- 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 in a solid phase vs gas phase
- Replies: 15
- Views: 1207
Re: dipole-dipole in a solid phase vs gas phase
Dipole-dipole in the solid phase is stronger than dipole-dipole in the gas phase.
- Sun Dec 01, 2019 1:15 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Amphoteric vs. Amphiprotic
- Replies: 4
- Views: 371
Re: Amphoteric vs. Amphiprotic
Amphiprotic substances can both accept and donate an H+ ion (proton). Amphoteric substances are both acidic and basic in character and can react with acids and bases.
- Sun Dec 01, 2019 1:06 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Sigma and Pi Bonds
- Replies: 12
- Views: 1099
Re: Sigma and Pi Bonds
A triple bond has one one sigma bond and two pi bonds.
- Sun Dec 01, 2019 1:00 am
- Forum: Naming
- Topic: Naming Coordination Compounds
- Replies: 3
- Views: 372
Naming Coordination Compounds
What are the steps in naming coordination compounds?
- Sun Nov 24, 2019 3:25 am
- Forum: Dipole Moments
- Topic: Dipole Induced- Dipole Induced
- Replies: 13
- Views: 1183
Re: Dipole Induced- Dipole Induced
Induced dipole - induced dipole forces are the weakest form of intermolecular forces and are present in all molecules.
- Sun Nov 24, 2019 3:21 am
- Forum: Hybridization
- Topic: Strength of sigma and pi bonds
- Replies: 8
- Views: 697
Re: Strength of sigma and pi bonds
The electrons in a sigma bond are directly between the nuclei of the atoms are as close to the nuclei as possible, so the nuclei strongly hold onto the electrons, making it difficult to break the bond. The electrons in a pi bond are further away from the nuclei, so the nuclei weakly attract the elec...
- Sun Nov 24, 2019 3:15 am
- 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 in a solid phase vs gas phase
- Replies: 15
- Views: 1207
Re: dipole-dipole in a solid phase vs gas phase
Dipole-dipole in the solid phase is stronger than dipole-dipole in the gas phase because the bonds in solids are stronger, thus the attraction between molecules is greater.
- Sun Nov 24, 2019 3:10 am
- Forum: Sigma & Pi Bonds
- Topic: Rotation
- Replies: 3
- Views: 244
Re: Rotation
Pi bonds consist of orbitals that are aligned side-by-side, in which one of the two orbitals cannot align in a different position to make the bond. Sigma bonds consist of orbitals that are aligned end-to-end, which allow them to rotate.
- Sun Nov 24, 2019 2:47 am
- Forum: Bronsted Acids & Bases
- Topic: Bronsted vs. Lewis Acids
- Replies: 4
- Views: 276
Re: Bronsted vs. Lewis Acids
Bronsted acids are are proton donors, while Lewis acids are electron acceptors. All Bronsted acids are Lewis acids, but not all Lewis acids are Bronsted acids.
- Sun Nov 17, 2019 10:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity
- Replies: 2
- Views: 193
Polarity
How do you predict the polarity of a molecule by its molecular shape?
- Sun Nov 17, 2019 10:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vsepr angles
- Replies: 10
- Views: 492
Re: vsepr angles
Yes, you should know the different orientations and bond angles for a particular shape.
- Sun Nov 17, 2019 10:02 pm
- Forum: Dipole Moments
- Topic: Effects for boiling point
- Replies: 5
- Views: 342
Re: Effects for boiling point
Increasing strength of intermolecular forces causes the boiling point to increase.
- Sun Nov 17, 2019 9:52 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: dipole moments
- Replies: 11
- Views: 651
Re: dipole moments
The dipoles are vectors, and when they are equal and opposite to to each other, they cancel out.
- Sun Nov 17, 2019 9:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lewis Structures
- Replies: 6
- Views: 618
Re: Lewis Structures
You can name the shape of the molecule by determining the number of the bound atoms and lone pairs around the central atom, which correlate to a certain shape.
- Sun Nov 10, 2019 10:59 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 and Melting Points
- Replies: 7
- Views: 545
Boiling and Melting Points
How do polarizability and the different intermolecular forces affect the boiling and melting points of compounds?
- Sun Nov 10, 2019 10:47 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizability
- Replies: 4
- Views: 359
Re: Polarizability
Larger atoms have more electrons and thus more shielding occurs. Thus, because electrons are at a greater distance from the nuclear charge and there is less attraction from the nucleus, the electrons are held more loosely, so the electron cloud is more susceptible to being distorted, making it more ...
- Sun Nov 10, 2019 10:38 pm
- Forum: Ionic & Covalent Bonds
- Topic: Bond Strength
- Replies: 3
- Views: 185
Re: Bond Strength
Ionic bonds are stronger due to the attraction between ions of opposite charges.
- Sun Nov 10, 2019 10:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Writing e- Configurations
- Replies: 15
- Views: 689
Re: Writing e- Configurations
It depends on what the question asks, it could either ask for the short-hand configuration, in which you would use the noble gas or the extended electron configuration,in which you would write out the full configuration.
- Sun Nov 10, 2019 10:26 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: Ion-ion interactions vs Ionic bonds
- Replies: 2
- Views: 154
Re: Ion-ion interactions vs Ionic bonds
Yes, ion-ion interactions occur between ions of opposite charges and are referred to as ionic bonds.
- Sat Nov 02, 2019 10:47 pm
- Forum: Lewis Structures
- Topic: Delocalized Electrons
- Replies: 4
- Views: 178
Re: Delocalized Electrons
Delocalized electrons are electrons that are not associated with a single atom or covalent bond, so essentially they have no specific location. Resonance structures depict delocalized bonding because they show bonds in different positions.
- Sat Nov 02, 2019 10:35 pm
- Forum: Empirical & Molecular Formulas
- Topic: Formula Units
- Replies: 2
- Views: 352
Re: Formula Units
Formula units usually apply to ionic compounds, while molecules apply to covalent compounds. In order to calculate formula units and molecules, convert the grams of Al2O3, convert it into moles, then use Avogadro's number 6.022 x 10^23 to find formula units and molecules.
- Sat Nov 02, 2019 10:25 pm
- Forum: Coordinate Covalent Bonds
- Topic: Atom Sharing
- Replies: 5
- Views: 350
Re: Atom Sharing
I believe that is the only difference: in coordinate covalent bonds, one atom donates two electrons to the bond and in covalent bonds, both atoms donate one electron to the bond.
- Sat Nov 02, 2019 10:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: Lewis Structure for Ionic Bonds
- Replies: 4
- Views: 159
Re: Lewis Structure for Ionic Bonds
The brackets go around ionic compounds that have a total net charge.
- Sat Nov 02, 2019 10:13 pm
- Forum: Limiting Reactant Calculations
- Topic: Test 1 Question
- Replies: 5
- Views: 584
Re: Test 1 Question
There is also another way you could solve the problem. In order to determine how many grams of glucose is left over, you would first need to determine how many grams of water the 10.0g of glucose produces. You would convert the grams of glucose that was initially present into moles. Then, you would ...
- Sun Oct 27, 2019 10:01 pm
- Forum: Ionic & Covalent Bonds
- Topic: periodic table
- Replies: 10
- Views: 414
Re: periodic table
Electronegativity increases up into the right of the periodic table.
- Sun Oct 27, 2019 9:36 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity vs. effective nuclear charge
- Replies: 5
- Views: 2097
Re: Electronegativity vs. effective nuclear charge
Electronegativity is essentially how much an atom pulls in electrons, whereas effective nuclear charge is how strongly an electron is attracted to the nucleus. They are directly proportional.
- Sun Oct 27, 2019 9:18 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic v. Covalent
- Replies: 7
- Views: 253
Re: Ionic v. Covalent
Covalent bonds are pairs of electrons that are shared between two non-metal atoms that have similar electronegativities. Ionic bonds form when electrons are transferred from a metal to non-metal atom, which differ significantly in electronegativity. Ionic bonds tend to be stronger than covalent bond...
- Sun Oct 27, 2019 9:00 pm
- Forum: Bond Lengths & Energies
- Topic: Delocalization
- Replies: 3
- Views: 178
Re: Delocalization
Eelectrons involved in resonance structures are delocalized. Electrons that appear in different positions in a set of resonance structures are said to be delocalized, meaning that a shared electron pair is distributed over several pairs of atoms and cannot be identified with just one pair of atoms.
- Sun Oct 27, 2019 8:38 pm
- Forum: Bond Lengths & Energies
- Topic: bond lengths for single or double bonds
- Replies: 7
- Views: 441
Re: bond lengths for single or double bonds
Bond lengths between atoms with multiple bonds are shorter than those with single bonds. Double bonds are shorter than single bonds, and triple bonds are shorter than double bonds.
- Sun Oct 20, 2019 6:55 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: magnetic quantum #
- Replies: 3
- Views: 165
Re: magnetic quantum #
Writing 2px, 2py, and 2pz is just an expanded notation of writing the orbitals. Each orbital is represented with a subscript x, y, z. If the 2p orbital is full, it would be 2px^2, 2py^2, 2pz^2. When writing the configuration of an atom with half filled orbitals, the p orbital for example would be 2p...
- Sun Oct 20, 2019 6:43 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Building Up Principle
- Replies: 2
- Views: 156
Re: Building Up Principle
The building up (Aufbau Principle) states that an electron occupies orbitals in order from lowest to highest energy. The lowest energy sublevel is the 1s sublevel, then as we go on to atoms with multiple electrons, the electrons are added on creating the 2s, 2p, 3s, etc. sublevels.
- Sun Oct 20, 2019 6:37 pm
- Forum: DeBroglie Equation
- Topic: When to use DeBrogile's Equation
- Replies: 4
- Views: 196
Re: When to use DeBrogile's Equation
DeBroglie's Equation is used for things or particles that have mass and that behave like a wave.
- Sun Oct 20, 2019 6:33 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum Numbers
- Replies: 5
- Views: 350
Re: Quantum Numbers
The magnetic quantum number tells us about the orientation of the orbitals in relation to other orbitals, which allows us to know more about the electron and its location in the atom.
- Sun Oct 20, 2019 6:21 pm
- Forum: DeBroglie Equation
- Topic: Particle-wave duality
- Replies: 2
- Views: 137
Particle-wave duality
What is the relationship between E=hv and E=mc^2 in the DeBroglie equation?
- Sun Oct 13, 2019 9:56 pm
- Forum: Properties of Light
- Topic: photoelectric effect
- Replies: 3
- Views: 154
Re: photoelectric effect
D. λv = c does not describe the photoelectric effect because the photoelectric experiment was designed to measure the how much energy is required to remove an electron from a metal surface and the kinetic energy of the electron, which is described by answers A, B, and C. Answer choice D describes th...
- Sun Oct 13, 2019 9:42 pm
- Forum: Photoelectric Effect
- Topic: Post Assessment Help
- Replies: 2
- Views: 203
Post Assessment Help
Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 10^5 m.s^-1. The work function for sodium is 150.6 kJ.mol^-1. What is the kinetic energy of the ejected electron? a) 3.01 x 10^25 J b) 3.98 x 10^-19 J c) 7.96 x 10^-19 J d) 1.99 x 10^-19 J How do you calculate the k...
- Sun Oct 13, 2019 9:31 pm
- Forum: Photoelectric Effect
- Topic: Wavelength, Frequency, and Intensity
- Replies: 7
- Views: 1173
Re: Wavelength, Frequency, and Intensity
A photon must have a wavelength that is lower than the threshold wavelength to have the required energy to eject electrons. According to the equation E = hv = hc/λ (λ being wavelength), having a long wavelength would decrease the energy needed to eject the electrons. Thus, having a shorter wavelengt...
- Sun Oct 13, 2019 9:12 pm
- Forum: Photoelectric Effect
- Topic: Equation for threshold energy
- Replies: 2
- Views: 206
Equation for threshold energy
How do we calculate the threshold energy, or the energy needed to remove an electron from a metal atom? What equation(s) would be used to calculate the threshold energy?
- Sun Oct 13, 2019 9:05 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 3
- Views: 219
Photoelectric Effect
Regarding the experiment in which long wavelength light does not eject electrons from a metal surface even with the increased intensity of the light, if it tells us that light not only has wavelike properties, then what other properties does it have?
- Sun Oct 06, 2019 5:27 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molar Mass
- Replies: 4
- Views: 182
Re: Molar Mass
You do not need to memorize the molar masses of all the elements. A periodic table will be provided. Sometimes molar masses of compounds will be given in the problem, but if not, you would have to use the periodic table to calculate the molar mass.
- Sun Oct 06, 2019 5:19 pm
- Forum: Limiting Reactant Calculations
- Topic: Step two in limiting reactants
- Replies: 3
- Views: 257
Re: Step two in limiting reactants
The question in the problem was "In one test the engine burns 1.00L of octane (of mass 702g) and produces 1.84kg of carbon dioxide. What is the percentage yield of carbon dioxide?" The problem asked us to calculate the percentage yield of carbon dioxide. It only gave us the actual yield of...
- Sun Oct 06, 2019 4:57 pm
- Forum: SI Units, Unit Conversions
- Topic: 50 Min test
- Replies: 4
- Views: 164
Re: 50 Min test
The test will take place during your discussion section.
- Sun Oct 06, 2019 4:56 pm
- Forum: Empirical & Molecular Formulas
- Topic: empirical and molecular formulas
- Replies: 7
- Views: 508
Re: empirical and molecular formulas
Yes, sometimes a compound's molecular formula can be the same as its empirical formula if the number of atoms in the empirical formula are the actual number of atoms in the molecular formula. The molecular formula can be the same as the empirical formula or a multiple of it. In a problem where it gi...
- Sun Oct 06, 2019 4:45 pm
- Forum: Limiting Reactant Calculations
- Topic: Reactant vs. Reagent
- Replies: 4
- Views: 300
Re: Reactant vs. Reagent
Chemicals in a lab are called reagents. When a reagent is used in a particular reaction, it is called a reactant.