Search found 56 matches
- Wed Dec 04, 2019 12:08 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis Structure of CH3S-
- Replies: 2
- Views: 831
Re: Lewis Structure of CH3S-
I think this compound is a lewis base as Sulphur atom has lone pairs on it and therefore, the compound can act as an electron pair donor.
- Wed Dec 04, 2019 12:05 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 2
- Views: 212
Re: Hybridization
Double bonds and triple bonds also count as only one region of electron density.
- Wed Dec 04, 2019 12:04 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: 6.4
- Replies: 1
- Views: 185
6.4
How many hydronium ions are present at any moment in 100. mL of pure water at 25 C?
- Tue Dec 03, 2019 9:48 pm
- Forum: Bronsted Acids & Bases
- Topic: Self-test6A.2B
- Replies: 3
- Views: 280
Re: Self-test6A.2B
Because Bronsted acids are defined to be the molecules to that donate a proton (H atom), NH4+ would be the Bronsted acid here as it is the one that donated a proton to HCO3- and became NH3. Lewis acids are defined to be the lone pair acceptors so NH4+ would be considered a Lewis acid since it is po...
- Mon Dec 02, 2019 12:25 pm
- Forum: Bronsted Acids & Bases
- Topic: Self-test6A.2B
- Replies: 3
- Views: 280
Self-test6A.2B
(a)Identify the Brønsted acids and bases in both reactants and products in the proton transfer equilibrium HCO3-(aq) + NH4+(aq) ---> H2CO3(aq) + NH3(aq).
(b) Which species (not necessarily shown explicitly) are Lewis acids and which are Lewis bases?
(b) Which species (not necessarily shown explicitly) are Lewis acids and which are Lewis bases?
- Mon Dec 02, 2019 12:08 pm
- Forum: Conjugate Acids & Bases
- Topic: Self-test 6A.1B
- Replies: 2
- Views: 218
Self-test 6A.1B
What is (a) the conjugate acid of H2O; (b) the conjugate base of NH3?
- Mon Dec 02, 2019 11:08 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Stability
- Replies: 1
- Views: 176
Re: Stability
I think this has to do with things like Ligand Field Theory and Crystal Field splitting, which we aren't going to be discussing in class
- Wed Nov 27, 2019 11:47 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Self-test 9C.2B
- Replies: 1
- Views: 174
Self-test 9C.2B
When excess silver nitrate is added to 0.0010 mol CrCl3.6H2O in aqueous solution, 0.0030 mol AgCl is formed. Which hydrate isomer is present?
- Wed Nov 27, 2019 11:13 am
- Forum: Naming
- Topic: Self-test 9C.1B
- Replies: 2
- Views: 231
Self-test 9C.1B
(a) Name the compound [CoBr(NH3)5]SO4.
(b) Write the formula of tetraamminediaquachromium(III) bromide.
(b) Write the formula of tetraamminediaquachromium(III) bromide.
- Mon Nov 25, 2019 9:04 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
Two chemists walk into a bar.
One says, “I’ll have an H2O.” The other says, “I’ll have an H2O, too.” The second chemist dies.
One says, “I’ll have an H2O.” The other says, “I’ll have an H2O, too.” The second chemist dies.
- Mon Nov 25, 2019 7:15 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: minimum coordination number
- Replies: 2
- Views: 175
Re: minimum coordination number
I think there are certain elements with coordination number 2 or 3 (CO3 2- has 3) but it's not very common.
- Mon Nov 25, 2019 7:13 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination sphere
- Replies: 1
- Views: 141
Re: coordination sphere
So the coordination sphere is essentially the entire coordination part of a compound. It includes the central metal atom and all the ligands that are connected to it.
- Mon Nov 25, 2019 7:10 am
- Forum: Administrative Questions and Class Announcements
- Topic: Points
- Replies: 11
- Views: 712
Re: Points
I think the TAs said you would be able to see it at the end of the quarter.
- Mon Nov 25, 2019 7:09 am
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: Ligands
- Replies: 5
- Views: 924
Re: Ligands
The coordintion number is correlation to the central metal atom as it speaks to how many ligands (or points of connection for bi/tridentate ligands) can connect to the central metal atom.
- Tue Nov 19, 2019 7:24 am
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 7
- Views: 621
Re: Octet Rule
The breaking of the octet rule occurs primarily when the element has empty d orbitals to use for bonding.
This aids in creating the lowest formal charge for the molecule as a whole, but is not directly correlated to making the formal charge for that particular atom zero.
This aids in creating the lowest formal charge for the molecule as a whole, but is not directly correlated to making the formal charge for that particular atom zero.
- Tue Nov 19, 2019 7:22 am
- Forum: Dipole Moments
- Topic: Cancelling Dipole Moments
- Replies: 4
- Views: 346
Re: Cancelling Dipole Moments
In general, the molecule doesn't have a net dipole when the orientation of species around the molecule is symmetrical, resulting in a cancelling of dipole moments. In the case of a tetrahedral geometry, the molecule only doesn't have dipole moment when all four species surrounding the central atom a...
- Tue Nov 19, 2019 7:18 am
- Forum: Dipole Moments
- Topic: Dipole Moment Arrows
- Replies: 1
- Views: 252
Re: Dipole Moment Arrows
The direction of the arrow indicates the direction of the dipole. So, dipole arrows should be drawn from positive to negative. That way, the direction the arrow points represents where an electron is more likely to be found.
- Tue Nov 19, 2019 7:16 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: Ion-Dipole
- Replies: 2
- Views: 410
Re: Ion-Dipole
An ion-dipole interaction is the result of an electrostatic interaction between a charged ion and a molecule that has a dipole. It is an attractive force that is commonly found in solutions, especially ionic compounds dissolved in polar liquids.
- Tue Nov 19, 2019 7:15 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: Strength of Intermolecular Forces
- Replies: 3
- Views: 283
Re: Strength of Intermolecular Forces
The boiling point of a molecule corresponds to the extent of Hydrogen bonding it undergoes - the greater the amount or strength of the hydrogen bonds, the higher the boiling point.
- Thu Nov 14, 2019 11:26 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
Q. How did the molecular spy introduce himself?
A. My name is Bond.. Covalent Bond.
A. My name is Bond.. Covalent Bond.
- Thu Nov 14, 2019 11:25 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
VSEPR jokes
- Thu Nov 14, 2019 11:18 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Repulsion
- Replies: 1
- Views: 161
Re: Repulsion
The bonding pair shared in a bond lies further from the atom than a nonbonding pair of that atom which is held close to its positively charged nucleus. Consequently, lone pairs are closer to each other than any other combination of pairs (lone pair-bonding pair and bonding pair-bonding pair), and th...
- Thu Nov 14, 2019 11:15 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electrons
- Replies: 9
- Views: 434
Re: Electrons
Electrons in an atom repel each other due to the fact that they have the same charge The strength of repulsion is such that lone pair- lone pair repulsions > Lone pair - bond pair repulsions > bond pair - bond pair repulsions Thus, by spreading the electrons and ensuring they're far away from each o...
- Tue Nov 12, 2019 9:34 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
Old Chemist One-Liner:
Old chemists never die, they just stop reacting
Old chemists never die, they just stop reacting
- Wed Nov 06, 2019 7:55 am
- Forum: Photoelectric Effect
- Topic: HW Question Focus 1, 1.3
- Replies: 1
- Views: 231
Re: HW Question Focus 1, 1.3
I first calculated the energy released per photon - which you get by using E = hc/lambda = 3.14 x 10^(-21) I then calculated the total energy released in a second by multiplying the energy per photon (which I found) with the number of photons produced. I got this value to be 7.536 J. Since the quest...
- Wed Nov 06, 2019 7:47 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: HW 2D.3
- Replies: 5
- Views: 580
Re: HW 2D.3
Ba is in the 2nd period of the periodic table i.e it has high metallic character and therefore very low electronegativity while Br is in the 17th period and therefore has high electronegativity. Due to this large difference, the bond is primarily ionic. In addition, on the test, you could also simpl...
- Wed Nov 06, 2019 7:44 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: How to write p in electron configuration
- Replies: 1
- Views: 223
Re: How to write p in electron configuration
We don't need to specify the orientation of the orbitals.
So we just need to write p^3
So we just need to write p^3
- Tue Nov 05, 2019 9:12 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
A covalent bond yelled at an ionic bond - Didn't anyone ever teach you how to share??
- Tue Nov 05, 2019 9:05 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: 1D.1
- Replies: 1
- Views: 109
1D.1
Which of the following increase when the electron in a hydrogen atom undergoes a transition from the 1s-orbital to a 2p-orbital? (a) Energy of the electron. (b) Value of n. (c) Value of l. (d) Radius of the atom.
- Fri Nov 01, 2019 11:19 am
- Forum: Coordinate Covalent Bonds
- Topic: Distinguishing a coordinate covalent bond
- Replies: 5
- Views: 247
Re: Distinguishing a coordinate covalent bond
By determining the difference in electronegativity between the elements.
- Fri Nov 01, 2019 11:18 am
- Forum: Lewis Structures
- Topic: Central atom
- Replies: 6
- Views: 233
Re: Central atom
The central atom is usually the one with the lowest electronegativity or the least numerous element.
- Wed Oct 30, 2019 4:07 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
Q: What emotional disorder does a gas chromatograph suffer from?
A: Separation anxiety.
A: Separation anxiety.
- Wed Oct 30, 2019 4:02 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionic vs covalent bonds
- Replies: 6
- Views: 255
Re: ionic vs covalent bonds
Yes, pretty much If the difference in electronegativities is greater than 2, the bond will be ionic If the difference in electronegativities is less than 1.5, the bond will be covalent for elements with difference in electronegativity between 1.5 and 2, the compounds will need to be taken on an indi...
- Wed Oct 30, 2019 4:00 pm
- Forum: Ionic & Covalent Bonds
- Topic: Self-test 2A.1B
- Replies: 1
- Views: 80
Self-test 2A.1B
Write the electron configurations of (a) the manganese(II) ion and (b) the
lead(IV) ion.
lead(IV) ion.
- Wed Oct 23, 2019 11:04 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity
- Replies: 2
- Views: 406
Re: Electron Affinity
Electron affinity describes the amount of energy released or spent when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion. It therefore tells us about the ease with which an electron can be added to a gaseous molecule. The general trend for electron affin...
- Wed Oct 23, 2019 10:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: ground state electron configurations
- Replies: 3
- Views: 221
Re: ground state electron configurations
I think this question can be solved by looking at a periodic table. (a) [Ar] 3d6 : No. of electrons in M ^+3 state = 18 + 6 = 24 Therefore no. of electrons in M = 24 + 3 = 27 Therefore M is Co (b) [Ar] 3d5 : No. of electrons in M^+3 state = 18 + 5 = 23 Therefore no. of electrons in M = 23 + 3 = 26 T...
- Wed Oct 23, 2019 12:32 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodal Planes
- Replies: 7
- Views: 364
Re: Nodal Planes
Hey! Is there any connection between the location of the nucleus and the nodal plane? Is the nucleus located on the nodal plane, since you cannot find an electron in the nucleus or the nodal plane? A nodal plane will generally include the position of the nucleus as, like you said, you cannot find a...
- Wed Oct 23, 2019 12:30 pm
- Forum: Trends in The Periodic Table
- Topic: Shielding
- Replies: 8
- Views: 543
Re: Shielding
Shielding is essentially the reduction in the effect of the nuclear charge from the nucleus felt by electrons in outer orbitals because they are blocked or "shielded" from the nucleus by the electrons in the inner orbitals
- Wed Oct 23, 2019 12:29 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.22
- Replies: 1
- Views: 104
1E.22
How many unpaired electrons are predicted for the ground-state configuration of each of the following atoms: (a) Pb; (b) Ir; (c) Y; (d) Cd?
- Wed Oct 23, 2019 12:25 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Self-test 1E.2B
- Replies: 2
- Views: 107
Self-test 1E.2B
Write the ground-state configuration of an arsenic atom.
- Thu Oct 17, 2019 4:16 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodal Planes
- Replies: 7
- Views: 364
Re: Nodal Planes
Nodal planes denote the areas in which the probability of finding electrons is zero.
Each orbital configuration (s,p,d and f) have different nodal planes.
Each orbital configuration (s,p,d and f) have different nodal planes.
- Wed Oct 16, 2019 1:29 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
Schrödinger and Heisenberg are driving down the motorway when a cop pulls them over. He walks up to the window and asks, "Sir, do you know how fast you were going?" Heisenberg replies, "No, but i know exactly where I was." The cop, thinking that such a weird response deserves fur...
- Wed Oct 16, 2019 1:22 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: 1D.4
- Replies: 1
- Views: 93
Re: 1D.4
For the second part of the question, what changes is the uncertainty in position, delta x. The range of the nuclear diameter is generally taken as 1.7 x 10^(-15) metres. Therefore, you substitute that value into the Heisenberg's indeterminacy equation and calculate the uncertainty in momentum You th...
- Tue Oct 15, 2019 11:22 pm
- Forum: Properties of Light
- Topic: 1A.6
- Replies: 3
- Views: 205
1A.6
Arrange the following types of photons of electromagnetic radiation in order of increasing frequency: visible light, radio waves, ultraviolet radiation, infrared radiation.
- Sun Oct 13, 2019 8:08 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Self-test 1B.5B
- Replies: 1
- Views: 114
Self-test 1B.5B
The police are monitoring an automobile of mass 2.0 t (1 t 5 103 kg) speeding along a highway. They are certain of the location of the vehicle only to within 1 m. What is the minimum uncertainty in the speed of the vehicle? Can you use as your defense the argument that the uncertainly principle prev...
- Sun Oct 13, 2019 9:41 am
- Forum: *Black Body Radiation
- Topic: Self-test 1B.1B
- Replies: 2
- Views: 162
Re: Self-test 1B.1B
Thank you!
- Sun Oct 13, 2019 9:40 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Self-test 1B.4B
- Replies: 2
- Views: 122
Self-test 1B.4B
Calculate the wavelength of a rifle bullet of mass 5.0 g traveling at twice the speed of sound (the speed of
sound is 331 m?s2 1).
sound is 331 m?s2 1).
- Fri Oct 11, 2019 11:01 am
- Forum: *Black Body Radiation
- Topic: Self-test 1B.1B
- Replies: 2
- Views: 162
Self-test 1B.1B
A red giant is a late stage in the evolution of a star. The average wavelength maximum at 700. nm shows that a red giant cools as it dies. What is the surface temperature of a red giant?
- Wed Oct 09, 2019 11:10 am
- Forum: Properties of Light
- Topic: Self-test 1A.1B
- Replies: 4
- Views: 127
Self-test 1A.1B
What is the wavelength of the signal from a radio station transmitting at
98.4 MHz?
98.4 MHz?
- Tue Oct 08, 2019 12:43 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3009656
Re: Post All Chemistry Jokes Here
Q: What kind of test do chemistry students like best?
A: Mole-tiple choice.
A: Mole-tiple choice.
- Fri Oct 04, 2019 12:12 am
- Forum: Molarity, Solutions, Dilutions
- Topic: G 13
- Replies: 3
- Views: 345
Re: G 13
To solve this we use the dilution law : M1V1 = M2V2. M1 = 0.20M . M2 = V1 = 1 l . V2 = 1 + 3 = 4 l Substituting in the equation, we get M2 = 0.05M Molarity = (No. of moles) divided by (volume in litres) Therefore, 0.05 = (n x 1000)/ 100 = 0.005 moles of NH4NO3 Each mole of NH4NO3 has 2 moles of N th...
- Thu Oct 03, 2019 8:34 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Self test G2B
- Replies: 1
- Views: 154
Self test G2B
Calculate the mass of oxalic acid needed to prepare 50.00 mL of 0.125 m C2H2O4(aq).
- Thu Oct 03, 2019 6:35 pm
- Forum: Empirical & Molecular Formulas
- Topic: F24
- Replies: 1
- Views: 265
F24
Dolomite is a mixed carbonate of calcium and magnesium. Calcium and magnesium carbonates both decompose upon heat- ing to produce the metal oxides (MgO and CaO) and carbon dioxide (CO2). If 5.12 g of residue consisting of MgO and CaO remains when 10.04 g of dolomite is heated until decomposition is ...
- Tue Oct 01, 2019 8:49 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Average molar mass
- Replies: 2
- Views: 200
Average molar mass
In the text under section E, in order to find the average molar mass for elements that have isotopes, they have first found the average atomic mass and then multiplied by Avogadro's constant to get the average molar mass. However, if in a question we are presented with the atomic mass, molar mass nu...
- Tue Oct 01, 2019 8:44 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity Self test E1B
- Replies: 2
- Views: 87
Re: Molarity Self test E1B
Thanks!
- Tue Oct 01, 2019 8:30 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molarity Self test E1B
- Replies: 2
- Views: 87
Molarity Self test E1B
A double espresso contains 3.14 mol H2O. What is the number of H atoms present in the espresso?