Search found 50 matches
- Sat Dec 07, 2019 3:02 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: relative acidity
- Replies: 5
- Views: 520
relative acidity
How is an anion stabilized?
- Sat Dec 07, 2019 2:51 pm
- Forum: Lewis Acids & Bases
- Topic: neutralization
- Replies: 6
- Views: 547
neutralization
Can neutralization only occur between a strong acid and metal hydroxide or can it occur between weak acids and bases as well?
- Sat Dec 07, 2019 2:46 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Thymine
- Replies: 1
- Views: 335
Thymine
What makes thymine a base?
- Sat Dec 07, 2019 2:39 pm
- Forum: Lewis Acids & Bases
- Topic: 6A.15
- Replies: 2
- Views: 220
Re: 6A.15
For part a, F- would donate an electron pair (lewis base) to the PF5, which accepts the electron pair (lewis acid). Therefore, the product would be PF6-.
- Sat Dec 07, 2019 2:35 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: polydentate ligands
- Replies: 1
- Views: 195
Re: polydentate ligands
A ligand is a polydentate if it donates at least 2 electron pairs.
- Sun Dec 01, 2019 6:15 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Difference between weak acids/bases and strong acids/bases
- Replies: 6
- Views: 387
Re: Difference between weak acids/bases and strong acids/bases
Strong acids and bases completely ionize while weak acids and bases only partially ionize. Strong acids produce many H+ ions and strong bases produce many OH- ions.
- Sun Dec 01, 2019 6:12 pm
- Forum: Conjugate Acids & Bases
- Topic: Acids and Bases
- Replies: 3
- Views: 268
Re: Acids and Bases
A conjugate acid is the species that is formed after the base accepts a proton, and a conjugate base is formed after an acid donates a proton. Bronsted acids are defined as H+ donors while Lewis acids are defined as electron pair acceptors.
- Sun Dec 01, 2019 6:08 pm
- Forum: Naming
- Topic: Naming coordination compounds
- Replies: 5
- Views: 351
Naming coordination compounds
How do you determine the roman numerals when naming a coordination compound, and how do you know you need to include them in the name?
- Sun Dec 01, 2019 6:03 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ligand
- Replies: 4
- Views: 329
Re: Ligand
A chelate is a complex containing a ligand that forms a ring of atoms that includes the central metal atom. For example, CuC2N2 is a chelate where a ring of atoms is formed including the central metal atom, copper.
- Sun Dec 01, 2019 5:54 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acids Vs. Bases
- Replies: 11
- Views: 841
Re: Acids Vs. Bases
Acids donate H+ ions(proton) and bases accept H+. Bases also produce OH- while acids produce H+. If you compare the hydrogens before and after a reaction, you can tell if the substance is an acid (decrease H+ =acid) or a base (increase=base).
- Sun Nov 24, 2019 9:20 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Sphere
- Replies: 5
- Views: 388
Re: Coordination Sphere
Ligands directly attached to the central ion make up the first coordination sphere, and the second coordination sphere consists of atoms/molecules attached to those in the first coordination sphere. Everything inside the brackets will be inside the coordination sphere.
- Sun Nov 24, 2019 9:13 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Transition Metals
- Replies: 7
- Views: 442
Transition Metals
Do all transition metals form coordination compounds or just the ones mentioned in lecture?
- Sun Nov 24, 2019 9:06 pm
- Forum: Ionic & Covalent Bonds
- Topic: ligands
- Replies: 7
- Views: 1646
Re: ligands
Ligands are electron pair donors that have at least one lone pair.
- Sun Nov 24, 2019 9:05 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand
- Replies: 10
- Views: 495
Re: Ligand
A ligand is also an electron pair donor, so it must have at least one or more lone pairs.
- Sun Nov 24, 2019 9:02 pm
- Forum: Sigma & Pi Bonds
- Topic: sigma and pi bonds
- Replies: 27
- Views: 1603
Re: sigma and pi bonds
Yes, and there are also two pi bonds and one sigma bond in a triple bond.
- Sun Nov 17, 2019 8:50 pm
- Forum: Lewis Structures
- Topic: Why can Xenon break the octet rule?
- Replies: 8
- Views: 5401
Re: Why can Xenon break the octet rule?
In Xenon Tetrafluoride (XeF4), it breaks the octet rule to achieve a formal charge of zero in addition to it being higher than n=3.
- Sun Nov 17, 2019 8:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 266
Re: Bond Angles
Linear: 180
Trigonal Planar: 120
Tetrahedral: 109.5
Trigonal Pyramidal: trigonal bond angles are 120 while the axial bond angles are 90 and 180
Octahedral: 90 and 180
If there are lone pairs, they repel so the bond angle is smaller.
Ex: NH3 has bond angles of 107 instead of 109.5
Trigonal Planar: 120
Tetrahedral: 109.5
Trigonal Pyramidal: trigonal bond angles are 120 while the axial bond angles are 90 and 180
Octahedral: 90 and 180
If there are lone pairs, they repel so the bond angle is smaller.
Ex: NH3 has bond angles of 107 instead of 109.5
- Sun Nov 17, 2019 8:34 pm
- Forum: Sigma & Pi Bonds
- Topic: sigma and pi bonds
- Replies: 4
- Views: 281
Re: sigma and pi bonds
Sigma bonds are also generally stronger than pi bonds and sigma can exist independently.
- Sun Nov 17, 2019 8:24 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angle
- Replies: 3
- Views: 218
Re: Bond angle
I believe we only need to know that it is less than a specific bond angle because it can differ for molecules such as H2O (104.5) and NH3 (107).
- Sun Nov 17, 2019 8:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 3
- Views: 204
Re: Bond Angles
The repulsion caused by the lone pairs results in a smaller bond angle. For example, NH3 is trigonal pyramidal because is has one lone pair and has a bond angle of 107 instead of 109.
- Sun Nov 10, 2019 6:28 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: Boiling point
- Replies: 5
- Views: 343
Re: Boiling point
Stronger bonds have higher boiling points because it takes more energy to boil. Ionic and Hydrogen bonds have higher boiling points while covalent bonds usually have lower boiling points.
- Sun Nov 10, 2019 5:27 pm
- Forum: Sigma & Pi Bonds
- Topic: sigma bonds
- Replies: 3
- Views: 291
Re: sigma bonds
A single bond has one sigma bond. In a double bond, there is one sigma and one pi bond. In a triple bond, there is one sigma bond and 2 pi bonds.
- Sun Nov 10, 2019 5:25 pm
- Forum: Dipole Moments
- Topic: Hydrogen bonding base pairs
- Replies: 4
- Views: 334
Hydrogen bonding base pairs
What is the difference between the AT and GC base pairs in the hydrogen bonding example used in lecture?
- Sun Nov 10, 2019 5:16 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Character
- Replies: 3
- Views: 292
Re: Covalent Character
Increasing covalent character is when the electrons get further from the nucleus and it becomes easier to share electrons with other atoms. As the polarizability of anion increase and the polarizing power of a cation increases, the covalent character also increases.
- Sun Nov 10, 2019 5:07 pm
- Forum: Electronegativity
- Topic: Iodine
- Replies: 6
- Views: 616
Re: Iodine
Because I2 is a bigger molecule, it has stronger London dispersion forces.
- Sat Nov 02, 2019 5:18 pm
- Forum: Lewis Structures
- Topic: Double Bonds vs. Lone Pairs
- Replies: 2
- Views: 138
Re: Double Bonds vs. Lone Pairs
After counting the number of valence electrons for each atom, use single bonds and put lone pairs on the atoms starting from the outside. Consider formal charge when drawing lewis structures to determine whether or not to use double bonds and make sure the total number of electrons matches that of t...
- Sat Nov 02, 2019 5:07 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: CNS- formal charge
- Replies: 2
- Views: 209
CNS- formal charge
In the lecture, we went over how the best version of CNS- is when the formal charge of -1 is on the S. Why is the formal charge of -1 on sulfur and not on nitrogen?
- Sat Nov 02, 2019 5:03 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Minimize formal charge of whole molecule?
- Replies: 7
- Views: 287
Re: Minimize formal charge of whole molecule?
Having the formal charge for each individual atom equal zero is usually best as well as minimizing the total formal charge.
- Sat Nov 02, 2019 4:59 pm
- Forum: Properties of Electrons
- Topic: Schrodinger Equation
- Replies: 2
- Views: 255
Re: Schrodinger Equation
Schrodinger's wave function equation uses the concept that an electron with wave-like properties and indeterminacy in momentum and position can be described by a wave function. This equation can also be solved for 1 electron atoms.
- Sat Nov 02, 2019 3:46 pm
- Forum: Ionic & Covalent Bonds
- Topic: Dissociation energy
- Replies: 3
- Views: 120
Re: Dissociation energy
The dissociation energy also increases as the difference between the electronegativity of atoms increases.
- Sat Oct 26, 2019 3:20 pm
- Forum: Lewis Structures
- Topic: 2B.1
- Replies: 2
- Views: 100
Re: 2B.1
The best structure would be with the double bond between oxygen and nitrogen and a single bond between nitrogen and fluorine since this would result in all the formal charges being zero (the best structure).
- Sat Oct 26, 2019 3:17 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: #1E17 help
- Replies: 1
- Views: 179
Re: #1E17 help
An electron will be removed from the 4s orbital because the 4s orbital has a lower energy than 3d. 4s has higher energy when when the 4s state is occupied AND electrons enter the 3d state.
- Sat Oct 26, 2019 3:04 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge Formula
- Replies: 5
- Views: 262
Formal Charge Formula
What are the shared electrons (S) for the formula FC= V -(L + (S/2)) and how do you count them?
- Sat Oct 26, 2019 3:01 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Expanded Valence Shells
- Replies: 5
- Views: 198
Re: Expanded Valence Shells
The elements P, S, and Cl can accommodate more than 8 valence electrons since atoms in period 3 or higher have d-orbitals that can accommodate more electrons.
- Sat Oct 26, 2019 2:58 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Checking bonding
- Replies: 3
- Views: 192
Re: Checking bonding
Comparing the formal charges of atoms in Lewis structures helps you find which is the more stable structure, but I'm not sure if this is the only method to see which is the best structure.
- Sun Oct 20, 2019 6:16 pm
- Forum: Properties of Light
- Topic: Question 1A.3
- Replies: 3
- Views: 150
Re: Question 1A.3
Because the waves broaden and the extent of change decreases when the frequency decreases, c is the correct answer.
- Sun Oct 20, 2019 6:11 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Magnetic Quantum Number ml
- Replies: 5
- Views: 235
Re: Magnetic Quantum Number ml
The magnetic quantum number labels different orbitals of a subshell (orientation) that an electron occupies.
- Sun Oct 20, 2019 6:08 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Configuration of 3d and 4s orbitals
- Replies: 1
- Views: 76
Configuration of 3d and 4s orbitals
Why is the electron configuration of scandium [Ar] 3d^1 4s^2 and not [Ar] 4s^2 3d^1 ?
- Sun Oct 20, 2019 6:02 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 5
- Views: 212
Re: Electron Configuration
You start using the d orbital after the 4s state since the 4s state is slightly lower energy than 3d.
- Sun Oct 20, 2019 5:56 pm
- Forum: DeBroglie Equation
- Topic: Wave properties module
- Replies: 2
- Views: 123
Re: Wave properties module
Electric cars do not have wavelike properties because the properties are negligible, and yes, you should convert it to m/s.
- Sun Oct 13, 2019 2:02 pm
- Forum: Properties of Light
- Topic: Speed of Light
- Replies: 3
- Views: 108
Re: Speed of Light
The wavelength changes, but the frequency remains constant in order to conserve energy.
- Sun Oct 13, 2019 1:58 pm
- Forum: Properties of Light
- Topic: EM waves
- Replies: 3
- Views: 132
Re: EM waves
Electromagnetic waves are the result of a disturbance in the electromagnetic field.
- Sun Oct 13, 2019 1:30 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectra for H
- Replies: 5
- Views: 186
Re: Atomic Spectra for H
The equation is En=-hR/n^2. This applies only to atoms with one electron (hydrogen) because if there were more, then they would repel each other.
- Sun Oct 13, 2019 12:22 pm
- Forum: DeBroglie Equation
- Topic: De Broglie Equation Clarification
- Replies: 4
- Views: 158
Re: De Broglie Equation Clarification
The wavelike properties are the diffraction patterns: constructive (waves in phase) and destructive interference (waves out of phase).
- Sun Oct 13, 2019 12:00 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: En=-hR/n^2
- Replies: 3
- Views: 318
Re: En=-hR/n^2
Yes I believe this is used to calculate the energy levels in hydrogen and will only work for atoms with a single electron.
- Thu Oct 03, 2019 11:14 am
- Forum: SI Units, Unit Conversions
- Topic: Dimensional Analysis Question
- Replies: 6
- Views: 325
Re: Dimensional Analysis Question
Yes you're right about using various ratios to get to the end answer. For example, when you are trying to convert 100 meters per sec to meters per minute, you would begin with the given 100m/s and multiply by the ratio 60sec/1 min since you are trying to solve for meters per minute. The seconds woul...
- Thu Oct 03, 2019 11:05 am
- Forum: Significant Figures
- Topic: Determining Sig Fig's
- Replies: 5
- Views: 336
Re: Determining Sig Fig's
Also make sure to only round for sig figs at the end of your calculations to ensure that you get the most accurate answer possible.
- Wed Oct 02, 2019 10:24 pm
- Forum: Significant Figures
- Topic: Question About Significant Figures and Rounding
- Replies: 22
- Views: 3170
Re: Question About Significant Figures and Rounding
I think for the molar masses given in the periodic table you should round to two places after the decimal, which I believe is generally the rule of thumb.
- Wed Oct 02, 2019 10:13 pm
- Forum: Balancing Chemical Reactions
- Topic: Fundamental H5 D
- Replies: 3
- Views: 165
Fundamental H5 D
To balance Fe2P (s) + S(s) -> P4S10 (s) + FeS(s), how do you know which element to start balancing first?
- Wed Oct 02, 2019 8:41 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig figs
- Replies: 18
- Views: 610
Re: Sig figs
For sig figs make sure to use the smallest value of sig figs in the given (ex. 4.00 is 3 sig figs) and also use at the end of calculations.