Search found 36 matches
- Fri Dec 07, 2018 10:16 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: Hydrogen bonding
- Replies: 1
- Views: 293
Re: Hydrogen bonding
H-bonding is generally the strongest because there is a high electronegative difference between the partially positive H and N, O or F which have high electronegativity values.
- Fri Dec 07, 2018 10:12 pm
- Forum: Bronsted Acids & Bases
- Topic: strong acid
- Replies: 2
- Views: 316
Re: strong acid
For determining relative acid strength (ie comparing which acid is stronger), electronegativity can help you determine which acid is stronger. The general guideline is that when looking at the conjugate bases of two acids, the molecule that has more electronegative atoms is the result of a stronger ...
- Fri Dec 07, 2018 10:06 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: strong vs weak acids
- Replies: 5
- Views: 642
Re: strong vs weak acids
You can determine relative acid strength based on two main factors: 1. bond length in relation to the acidic proton (longer bond, stronger acid) 2. resulting anion stability (more stable conjugate base, stronger acid) But to differentiate strong acids vs weak acids, usually you have to just memorize...
- Fri Dec 07, 2018 12:28 am
- Forum: Bronsted Acids & Bases
- Topic: 7th ed 6A.9 c
- Replies: 1
- Views: 256
7th ed 6A.9 c
For this question, it asks if the reaction is between a Bronsted acid and base.
(c)CH3COOH + NH3 -> CH3CONH2 + H2O
The answer in the solution says that there is no proton transferred. Can someone explain what's happening and why there isn't?
(c)CH3COOH + NH3 -> CH3CONH2 + H2O
The answer in the solution says that there is no proton transferred. Can someone explain what's happening and why there isn't?
- Sat Dec 01, 2018 8:52 pm
- Forum: Hybridization
- Topic: lone pairs
- Replies: 20
- Views: 2174
Re: lone pairs
Yes the lone pairs are taken into account since the number of hybrid orbitals is equal to the number of regions of e- density around the atom.
- Sat Dec 01, 2018 8:51 pm
- Forum: Electronegativity
- Topic: Trend of Electronegativity
- Replies: 18
- Views: 4265
Re: Trend of Electronegativity
Yes they have similar trends. Both increase as you move right across a period and up a group/family.
- Sat Dec 01, 2018 8:50 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: polarizing power and polarizability
- Replies: 5
- Views: 702
Re: polarizing power and polarizability
The polarizability of anions increases as the ion gets larger and less electronegative.
Meanwhile, the polarizing power of cations increases as the ion gets smaller and more highly charged.
Meanwhile, the polarizing power of cations increases as the ion gets smaller and more highly charged.
- Mon Nov 26, 2018 11:32 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Compounds and Ligands
- Replies: 1
- Views: 256
Coordination Compounds and Ligands
Hi so I still don't really understand the importance of coordination compounds and what exactly ligands do. If someone could explain them to me that would be great! Thanks!
- Tue Nov 20, 2018 3:17 pm
- Forum: Hybridization
- Topic: E- Promotion vs Hybridization
- Replies: 1
- Views: 537
E- Promotion vs Hybridization
Can someone please explain the difference between e- promotion and hybridization? Thanks!
- Tue Nov 20, 2018 3:10 pm
- Forum: Hybridization
- Topic: 7th Edition 2F.15
- Replies: 1
- Views: 296
Re: 7th Edition 2F.15
The s-character is how much the sigma bond contributes to the hybridization.
For example, sp3 orbitals have 25% s-character and 75% p-character, while sp orbitals have 50% s-character and 50% p-character.
For example, sp3 orbitals have 25% s-character and 75% p-character, while sp orbitals have 50% s-character and 50% p-character.
- Tue Nov 20, 2018 3:06 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining Location of Lone Pair
- Replies: 1
- Views: 262
Re: Determining Location of Lone Pair
It matters when you are drawing the 3D structure and determining the molecular geometry of the molecule. Since the lone pair would want to be in the area where it interacts with the least amount of other atoms, it would be in the equatorial plane with the 2 F atoms, while the 2 O atoms will be on th...
- Sat Nov 17, 2018 4:10 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw shape
- Replies: 2
- Views: 297
Re: Seesaw shape
Molecules have the see-saw shape if they have the AX4E VSEPR notation which means they have 4 bonding pairs and 1 lone pair around the central atom.
- Sat Nov 17, 2018 2:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs of Electrons
- Replies: 1
- Views: 246
Re: Lone Pairs of Electrons
To determine if there is a lone pair, you would generally look at the angles between atoms. If there is a smaller bond angle than expected, there must be electron repulsion resulting from lone pairs. However, lone pair repulsion could also cancel each other out, so you should base it on the placemen...
- Sat Nov 17, 2018 2:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawings of Molecular Shape
- Replies: 2
- Views: 291
Re: Drawings of Molecular Shape
Although we probably won't be asked to draw molecules in 3D, it definitely helps to know how the atoms would be arranged in a three-dimensional space to determine things such as polarity and shape.
- Fri Nov 16, 2018 2:25 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
- Replies: 8
- Views: 2267
H-Bonding
If a molecule has H-atoms does that mean there is always H-bonds as intermolecular forces? Are there any exceptions?
- Sun Nov 11, 2018 2:26 pm
- Forum: Dipole Moments
- Topic: Dipole moment
- Replies: 4
- Views: 453
Re: Dipole moment
To determine dipole moment, you would normally base it upon the forces present within the molecule and between molecules. So, the larger the difference in electronegativity, the larger the net dipole moment. For example, ionic bonds have higher dipole while covalent bonds do not.
- Sun Nov 11, 2018 2:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR determining shape
- Replies: 3
- Views: 354
Re: VSEPR determining shape
To determine, the shape (molecular geometry) of a molecule, you would have to consider the number of electron groups which comprises of both bonding pairs and lone pairs.
- Sun Nov 11, 2018 2:18 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acid vs base [ENDORSED]
- Replies: 15
- Views: 1597
Re: Acid vs base [ENDORSED]
A Lewis Base is a species that donate e- pairs (ie. NH3, F-, OH-). While, a Lewis Acid is one that accepts e- pairs (ie. BF3, H+).
- Fri Nov 02, 2018 5:55 pm
- Forum: Trends in The Periodic Table
- Topic: Cation and Anion Size
- Replies: 3
- Views: 465
Re: Cation and Anion Size
Cations are smaller because since they have less electrons than their parent atoms, they are pulled in more closely by the protons (which are unchanged) in the nucleus. The opposite goes for anions where they have increased electron repulsion.
- Fri Nov 02, 2018 5:52 pm
- Forum: Properties of Electrons
- Topic: Energy of an Electron
- Replies: 2
- Views: 613
Re: Energy of an Electron
Usually, to calculate the energy of an (ejected) electron, you would need to know the velocity using the equation mv^2 / 2. So, I do not think that you would be asked to calculate the energy when you are only given the wavelength. The equation E=hv is meant for calculations pertaining to light (and ...
- Fri Nov 02, 2018 2:17 pm
- Forum: Ionic & Covalent Bonds
- Topic: Highly Distorted Electrons?
- Replies: 3
- Views: 307
Highly Distorted Electrons?
During today's lecture, there was a slide that said "Highly distorted electrons are described as being highly polarizable." Can someone please explain what this means? And also how do you know if the electrons are highly distorted? Thanks!
- Fri Oct 26, 2018 9:24 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Principal Quantum Number - Periodic Table
- Replies: 2
- Views: 341
Re: Principal Quantum Number - Periodic Table
I think it also has to do with the fact that the atomic numbers of 3d are larger than 4s so it would make more sense if they would be arranged after it, on the same row.
ie. Sc (which has a 3d orbital) has 21 protons or electrons while Ca (which only has up to 4s) has 20 protons or electrons.
ie. Sc (which has a 3d orbital) has 21 protons or electrons while Ca (which only has up to 4s) has 20 protons or electrons.
- Fri Oct 26, 2018 9:02 pm
- Forum: Ionic & Covalent Bonds
- Topic: Valence Electrons
- Replies: 3
- Views: 346
Re: Valence Electrons
In the case of covalent bonds, since the shared electrons help satisfy its electrons needs (or the octet guideline), those electrons are also attracted to the nuclei of the other atom, keeping it more stable.
- Fri Oct 26, 2018 8:58 pm
- Forum: *Shrodinger Equation
- Topic: Quantum spin number and wave function
- Replies: 1
- Views: 537
Re: Quantum spin number and wave function
The derivation of the Spin Quantum Number is based upon the Pauli Exclusion Principle. So, although the spin number is not part of the Wave Function, it helps completely specify an e- in an atom particularly spin state.
- Thu Oct 25, 2018 3:22 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Calculating Uncertainty in Momentum
- Replies: 3
- Views: 495
Re: Calculating Uncertainty in Momentum
In calculating uncertainty in momentum, you would normally use the value for diameter. But in the example you gave, they gave a specific section of the atom wherein the position of an electron could be found. So you would use the given (which is 1% of radius) to calculate the uncertainty in position...
- Thu Oct 18, 2018 12:33 pm
- Forum: Properties of Light
- Topic: Corresponding Wavelength/Frequency for Each Type of Wave?
- Replies: 2
- Views: 253
Corresponding Wavelength/Frequency for Each Type of Wave?
I saw that in a few numbers in the textbook practice problems ask for the type of wave that corresponds with the wavelength/frequency you solved. I was just wondering if there is a strict range (ie. 400-700nm) for each wave type on the electromagnetic spectrum. Thanks!
- Thu Oct 18, 2018 12:25 pm
- Forum: Properties of Light
- Topic: Problem 1.3, Seventh edition
- Replies: 1
- Views: 188
Re: Problem 1.3, Seventh edition
Because this problem states that the given values produced occur "in each second", the value for watts and joules would be the same (aside from the difference in units).
- Wed Oct 17, 2018 11:00 pm
- Forum: SI Units, Unit Conversions
- Topic: Significant Figures for Adding Numbers in Scientific Notation
- Replies: 2
- Views: 348
Significant Figures for Adding Numbers in Scientific Notation
I know that the rule for significant figures for adding numbers is to follow the least amount of decimal places. However, I was wondering how that would work for numbers in scientific notation. Ex. In adding 1.11 x 10^-9 and 1.1 x 10^-10, since they virtually have the same amount of decimal places w...
- Wed Oct 17, 2018 9:10 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Problem 1A.15
- Replies: 1
- Views: 112
Re: Problem 1A.15
For this you would use the equation relating the speed of light to wavelength and frequency [ c = λv ] to first solve for the frequency. Afterwards, you could use the Rydberg equation [ v = R ( 1/n1^2 - 1/n2^2 ) ] to solve for the final energy level.
- Thu Oct 11, 2018 10:32 pm
- Forum: Properties of Light
- Topic: Question 1B.7 7th Edition
- Replies: 2
- Views: 225
Re: Question 1B.7 7th Edition
Using the equations E=hv and c=λv, you can derive the equation E = hc/λ which solves for the amount of energy emitted by one atom when it generates a photon. You know the values of λ = 589nm or 589 x 10^-9m as well as the constants h (Planck's constant) and c (speed of light). So for (a): E = hc/λ E...
- Thu Oct 11, 2018 10:23 pm
- Forum: Properties of Light
- Topic: Intensity
- Replies: 2
- Views: 145
Re: Intensity
Intensity can be measured by W/m^2 (watts per square meter).
- Thu Oct 11, 2018 10:17 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Formula M1V1=M2V2 [ENDORSED]
- Replies: 5
- Views: 6510
Re: Formula M1V1=M2V2 [ENDORSED]
In G13, you still use that formula to some extent to solve the molarity of NH4NO3, although the calculation is not shown in the solution manual. The equation M1V1=M2V2 becomes (0.20 M) (1.0 L) = (x) (1.0 + 3.0 L) which leads to the knowledge that the molarity of the diluted solution is 0.050 M. You ...
- Wed Oct 10, 2018 11:51 pm
- Forum: SI Units, Unit Conversions
- Topic: Should Significant Figures be affected by constants?
- Replies: 10
- Views: 991
Should Significant Figures be affected by constants?
I am a confused by whether significant figures in solutions should be limited by the number of significant figures in constants. For example: If my given frequency is 5.11111 x 10^14 Hz (6 Significant Figures) and the constant for speed of light I use is 3.00 x 10^8 m/s (3 Significant Figures), shou...
- Thu Oct 04, 2018 11:30 pm
- Forum: Limiting Reactant Calculations
- Topic: Volume of Solution
- Replies: 2
- Views: 292
Re: Volume of Solution
If you are talking about question G5 in the textbook, these are the steps you would need to take. First solve for the molar mass of Na2CO3. Na2CO3= (22.99x2)+12.01+(16.00x3) = 105.99g/mol Solve for the molarity of Na2CO3. M = 2.111g / [(105.99g/mol)(0.2500 L) = 0.07967 M You would then need to incor...
- Thu Oct 04, 2018 5:00 pm
- Forum: Limiting Reactant Calculations
- Topic: Question 7 on Module 1 Post-Assessment [ENDORSED]
- Replies: 2
- Views: 2825
Re: Question 7 on Module 1 Post-Assessment [ENDORSED]
You can assume a 100g sample since the percentages add up to 100g to first find the empirical formula. C:74.03g/12.01g/mol = 6.164mol H:8.70g/1.01g/mol = 8.614mol N:17.27g/14.01g/mol = 1.233mol Simplify the ratios by dividing by the smallest result and rounding up. C:6.164/1.233 = 5 H:8.614/1.233 = ...
- Tue Oct 02, 2018 4:55 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Would it be acceptable to use the term concentration (C) for molarity (M) of a solution?
- Replies: 3
- Views: 379
Re: Would it be acceptable to use the term concentration (C) for molarity (M) of a solution?
I think for the sake of uniformity, it would be better to use M for molarity because there are several ways concentration can be denoted (ie. molality). It's just for the sake of having a specific unit. Also, since we would be using the carbon element a lot which is also denoted by C, it might becom...