Search found 101 matches
- Mon Mar 15, 2021 12:06 am
- Forum: *Enzyme Kinetics
- Topic: intermediates vs. catalysts
- Replies: 31
- Views: 1235
Re: intermediates vs. catalysts
Similar to everyone else I noticed that intermediates are always produced so they would enter an equation as a product, while catalysts are always added so they would enter an equation as a reactant.
- Mon Mar 15, 2021 12:03 am
- Forum: Zero Order Reactions
- Topic: Overall order of the reaction
- Replies: 45
- Views: 1660
Re: Overall order of the reaction
The overall order of a reaction is determined by adding the orders of each reactant in the rate law equation.
- Mon Mar 15, 2021 12:01 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Slowest step
- Replies: 38
- Views: 1325
Re: Slowest step
The slowest step is the rate determining step as the reaction can only go as fast as the slowest step. So the reaction has to wait for this step in the reaction to finish before it can come to completion.
- Sun Mar 14, 2021 11:59 pm
- Forum: General Rate Laws
- Topic: Intermediate
- Replies: 59
- Views: 3401
Re: Intermediate
An intermediate is a reagent in a reaction that is both created and used up during a chemical reaction (in different steps of course).
- Sun Mar 14, 2021 11:58 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: What was your favorite chem topic?
- Replies: 137
- Views: 7836
Re: What was your favorite chem topic?
My favorite chem topic has to be thermodynamics, to me that was the most interesting and it was actually the topic that I understood the most!
- Sun Mar 07, 2021 10:55 pm
- Forum: Second Order Reactions
- Topic: Termolecular
- Replies: 43
- Views: 2138
Re: Termolecular
Termolecular is essentially a third order, but this is very rare and I don't think we necessarily need to know too much about this.
- Sun Mar 07, 2021 10:52 pm
- Forum: First Order Reactions
- Topic: Finding order through graphs
- Replies: 17
- Views: 978
Re: Finding order through graphs
I don't know if we will necessarily be told to figure out thw order of graphs, but we will most likely be told to figure out the order of a reaction using the graphs. So we will probably be given three graphs (of zeroth, first and second order) and we will determine which is the most linear. The mos...
- Sun Mar 07, 2021 10:46 pm
- Forum: Second Order Reactions
- Topic: Finding out order
- Replies: 22
- Views: 902
Re: Finding out order
Yes, the constant k has different units for each order. The zeroth order has the units of M/s, the first order has the units 1/s, and the second order has the units of 1/M*s. With this, if we know the units of the k of the rate law then we can figure out which order each reagent is in.
- Sun Mar 07, 2021 10:42 pm
- Forum: First Order Reactions
- Topic: Slope
- Replies: 24
- Views: 788
Re: Slope
The slope is equal to - k for the zeroth and first order. For the second order the slope is equal to +k
- Sun Feb 28, 2021 5:41 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode/Cathode
- Replies: 45
- Views: 1395
Re: Anode/Cathode
The anode is always on the left while the cathode is always on the right. This is essential to show the direction of the flow of electrons.
- Sun Feb 28, 2021 5:38 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Moles in ΔG = -nFE
- Replies: 45
- Views: 3542
Re: Moles in ΔG = -nFE
In this case the n is measuring the moles of electrons. So we would balance the half reactions and count the amount (moles) of electrons transferred.
- Sun Feb 28, 2021 4:54 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: What is Potential?
- Replies: 14
- Views: 557
Re: What is Potential?
Yeah so standard reaction potential is essentially measures the likelihood of reduction (the gaining of electrons) occurring in the species.
- Sun Feb 28, 2021 4:47 pm
- Forum: Balancing Redox Reactions
- Topic: adding water in the reaction
- Replies: 13
- Views: 577
Re: adding water in the reaction
Water is added to redox reactions in order to balance the amount of oxygen atoms on both sides. On the other side of the reaction, in basic solutions (where water is not being added), OH- is usually added.
- Sun Feb 28, 2021 4:42 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation vs Reduction
- Replies: 30
- Views: 1212
Re: Oxidation vs Reduction
Similarly, I also learned about the acronym OIL RIG in my high school chemistry class. So Oxidation Is the Loss of electrons while Reduction Is the Gain of electrons. When losing electrons the net charge becomes more positive and when gaining electrons the net charge becomes more negative.
- Sun Feb 21, 2021 10:32 pm
- Forum: Van't Hoff Equation
- Topic: ln
- Replies: 34
- Views: 1745
Re: ln
It is e to the power of the value on the opposite side
- Wed Feb 17, 2021 3:39 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta H and Delta S both positive
- Replies: 31
- Views: 7801
Re: Delta H and Delta S both positive
When both delta H and delta S are positive then that means that the reaction will be spontaneous at high temperatures. Since we are subtracting two positive numbers we will want delta S to be larger than delta H so that delta G can be negative. This is why it would be spontaneous at higher temperatu...
- Wed Feb 17, 2021 3:33 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Units of W
- Replies: 16
- Views: 683
Re: Units of W
Yeah W does not have any units as it essentially just numbers the amount of possible states.
- Wed Feb 17, 2021 3:29 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: qrev
- Replies: 27
- Views: 1440
Re: qrev
qrev stands for the amount of heat energy transferred in a reversibile reaction.
- Wed Feb 17, 2021 3:26 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Meaning of K
- Replies: 55
- Views: 3605
Re: Meaning of K
Yeah for thermodynamics K can either be used as an abbreviation for the units Kelvin or as the equilibrium constant!
- Mon Feb 15, 2021 12:12 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Kelvin conversion
- Replies: 40
- Views: 2643
Re: Kelvin conversion
I have seen kelvin conversions using both 273 and 273.15 so I don't think it matters too much, we should end up with the same answer anyway. So converting Celsius to Kelvin would be either C + 273 or C + 273.15.
- Mon Feb 15, 2021 12:07 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isothermal Reactions
- Replies: 26
- Views: 1141
Re: Isothermal Reactions
Yes, isothermal reactions are reversible since they maintain the same temperature throughout the reaction.
- Mon Feb 15, 2021 12:05 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Sign of work
- Replies: 17
- Views: 668
Re: Sign of work
Work is positive when if work is being done to the system (gaining energy), and it is negative if the system is doing work(losing energy).
- Mon Feb 15, 2021 12:03 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Free Energy
- Replies: 49
- Views: 1809
Re: Free Energy
A state function is a function that doesn't depend on the path taken to get to a final answer, as long as this function begins and ends with the same value. Free energy is a state function as the path taken to to get to the final value does not really matter.
- Mon Feb 15, 2021 12:00 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Entropy
- Replies: 27
- Views: 1000
Re: Entropy
Entropy represents the unavailability of a system's thermal energy for conversion into mechanical work. It is also usually described as a degree of disorder. Entropy is incredibly important for the midterm that is coming up!
- Sun Feb 07, 2021 11:05 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Work
- Replies: 39
- Views: 1356
Re: Work
If work is negative that means that the system is doing work, so energy is going to be required in order to do the work.
- Sun Feb 07, 2021 11:02 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: deltaU
- Replies: 29
- Views: 740
Re: deltaU
Delta U is essentially the change in the internal energy of a system.
- Sun Feb 07, 2021 11:00 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: R Constant
- Replies: 91
- Views: 4972
Re: R Constant
Yeah we just meed to make sure that the units of the R match the units given in the problem.
- Sun Feb 07, 2021 10:58 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Extensive vs Intensive
- Replies: 10
- Views: 305
Re: Extensive vs Intensive
Extensive properties depend on the amount of matter being measured, such as mass and volume. Intensive properties do not, such as density and color.
- Sun Feb 07, 2021 10:56 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed System
- Replies: 52
- Views: 2476
Re: Closed System
It is still exhanging energy with its surroundings and can still move in and out. A closed system is different to an insulated system, in an insulated system energy is not exchanged with its surroundings.
- Sun Feb 07, 2021 10:52 pm
- Forum: Balancing Redox Reactions
- Topic: Cathode and Anode
- Replies: 24
- Views: 1437
Re: Cathode and Anode
Since the point of equilibrium has not been reached yet, then the cathod e cell would have to continue working. 0 is when the e cell stops working so we would want it to be a positive value to continue working.
- Wed Feb 03, 2021 1:11 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: change in celsius = change in kelvin
- Replies: 22
- Views: 7462
Re: change in celsius = change in kelvin
So although they are different units, in both cases, a degree change in celsius will lead to a degree change in kelvin. So since 1 C is 274 K then 2 C is 275 K and etc.
- Wed Feb 03, 2021 1:08 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat released/ gained
- Replies: 22
- Views: 890
Re: Heat released/ gained
Energy is required to break bonds and energy is released when forming bonds.
- Wed Feb 03, 2021 1:06 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Memorize bond enthalpies / standard enthalpies of formation?
- Replies: 39
- Views: 1205
Re: Memorize bond enthalpies / standard enthalpies of formation?
I am pretty sure we will not be expected to memorize anybond enthalpies or standard enthalpies. They will likely be given to us.
- Wed Feb 03, 2021 1:03 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard Enthalpies of Formation using Hess's Law
- Replies: 18
- Views: 948
Re: Standard Enthalpies of Formation using Hess's Law
Yes, it can be rearranged but we have to make sure to keep track of which direction they end up in so that we can change the enthalpy's sign accordingly.
- Wed Feb 03, 2021 1:00 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Hess's Law
- Replies: 58
- Views: 2725
Re: Hess's Law
The law basically states that if a reaction take place by more than one route then the total enthalpy change will be the same. So enthalpy is a state function and can be summed.
- Sun Jan 24, 2021 5:58 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increase in Pressure
- Replies: 31
- Views: 661
Re: Increase in Pressure
This would only apply to gases, not liquids
- Sun Jan 24, 2021 5:53 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Deprotonation Percentage Formula
- Replies: 6
- Views: 190
Re: Deprotonation Percentage Formula
The formula is the (equilibrium constant/initial concentration of HA) x 100%
- Sun Jan 24, 2021 5:49 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Weak vs. Strong Acids and Bases
- Replies: 9
- Views: 510
Re: Weak vs. Strong Acids and Bases
I would say that the only and probably easiest way is to just memorize the list of strong acids and bases. With this all the acids and bases that aren't listed as strong would be considered weak.
- Sun Jan 24, 2021 5:46 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Rounding E Values in ICE charts
- Replies: 17
- Views: 575
Re: Rounding E Values in ICE charts
I remember in lecture Lavelle saying that if the k value is 10^-4 or smaller then x can be omitted in the E section of the ICE table.
- Sun Jan 24, 2021 5:40 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Ka correlation to strength of an acid
- Replies: 30
- Views: 2047
Re: Ka correlation to strength of an acid
The larger the Ka value, the stronger the acid. The larger the Kb value, the stronger the base.
- Sun Jan 17, 2021 11:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: What makes a weak acid?
- Replies: 11
- Views: 252
Re: What makes a weak acid?
Yeah I would say that the memorizing the list of strong acids and strong bases would help out a lot for this. Since if they are not on the list then they are automatically considered weak. Well weak in comparison to the listed strong acids and bases.
- Sun Jan 17, 2021 11:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Initial Concentrations
- Replies: 7
- Views: 284
Re: Initial Concentrations
We are usually given the initial concentrations of the reactants and so we put those in the ICE table. For the most part the reactants will be 0 if we are not given them since it is basically saying that they have not been formed yet.
- Sun Jan 17, 2021 10:59 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Total pressure calculation
- Replies: 8
- Views: 971
Re: Total pressure calculation
By adding all of the partial pressure values you can get the total pressure.
- Sun Jan 17, 2021 10:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: C in ICE Box
- Replies: 19
- Views: 610
Re: C in ICE Box
Yeah, when you are losing reactant then the reactant's change would be negative and with that the product's change would be positive since you are gaining some. This could also be done in the reverse order so gaining reactant and losing product.
- Sun Jan 17, 2021 10:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Box
- Replies: 28
- Views: 1114
Re: ICE Box
For the ICE method I think we generally just use it for weak bases and acids, and I guess if you are unsure on whether the base or acid is strong then it may be safe to still use the ICE method.
- Sun Jan 10, 2021 11:12 pm
- Forum: Ideal Gases
- Topic: reversing reactions
- Replies: 83
- Views: 4717
Re: reversing reactions
When reversing a reaction, the value of K becomes the inverse of the forward reactions K (1/K).
- Sun Jan 10, 2021 11:07 pm
- Forum: Ideal Gases
- Topic: Inert Gas
- Replies: 20
- Views: 513
Re: Inert Gas
I too was confused on what Dr. Lavelle meant by "inert gas", but it basically is just another word for noble gas. These gases are usually unreactive.
- Sun Jan 10, 2021 11:05 pm
- Forum: Ideal Gases
- Topic: T variable in pv=nrt [ENDORSED]
- Replies: 38
- Views: 1492
Re: T variable in pv=nrt [ENDORSED]
Dr. Lavelle stated in lecture that we will almost always use Kelvin when working with temperature in equations.
- Sun Jan 10, 2021 11:00 pm
- Forum: Ideal Gases
- Topic: value of R
- Replies: 24
- Views: 907
Re: value of R
It all just depends on the units that we are using. Each different value of R is essentially the same, they are only different because they are given in different units.
- Sun Jan 10, 2021 10:58 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 4273
Re: Kc vs Kp
Kc is used when the concentrations of reactants and products are given for a solution. Kp is used when the partial pressure is given for a gas.
- Wed Dec 16, 2020 11:45 pm
- Forum: Naming
- Topic: Latin names
- Replies: 10
- Views: 618
Re: Latin names
We would only use the Latin names for anions
- Wed Dec 16, 2020 11:42 pm
- Forum: Biological Examples
- Topic: Hemoglobin vs. Myoglobin
- Replies: 30
- Views: 1167
Re: Hemoglobin vs. Myoglobin
There are just present in different locations. So hemoglobin is present in the blood while myoglobin is present in muscle tissue
- Wed Dec 16, 2020 11:37 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: shape
- Replies: 6
- Views: 358
Re: shape
To my understanding an example of a tetrahedral is a lot more common than that of square planar, but Dr. Lavelle said in lecture that we wouldn't necessarily need to know which of the two shapes it is. All we need to know is that it can be either of the two shapes.
- Wed Dec 16, 2020 11:34 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Cis Trans Isomers
- Replies: 7
- Views: 353
Re: Cis Trans Isomers
Cis isomers are when two of the same ions are on the same side. This means that there are dipole moments present in the isomer. Trans isomers are when the ions are on opposite sides. So this means that the dipole moments essentially cancel each other out.
- Wed Dec 16, 2020 11:31 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Square planar complex vs tetrahedral complex
- Replies: 6
- Views: 2861
Re: Square planar complex vs tetrahedral complex
Yeah so the only difference is that the tetrahedral complex has four bonds so it is attached to four ligands, while the square planar has only 3 bonds and a lone pair of electrons which counts as the fourth region of electron density.
- Sun Dec 06, 2020 7:41 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Memorization for final
- Replies: 9
- Views: 396
Re: Memorization for final
My TA told us that we should try and memorize the VSEPR models as it will help us out a lot when taking the final.
- Sun Dec 06, 2020 7:38 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Number and Regions of density
- Replies: 8
- Views: 708
Re: Coordination Number and Regions of density
The coordinatiom number describes the number of bonds the central atom formed so it does not necessarily look at electrons. Also, in regions of density lone electron pairs are considered regions of density and this has no correlation with the coordination number.
Re: Sapling
En stands for Ethylenediamine and basically donates a pair of electrons to a metal.
Re: -ate
When using -ate we have to first look at whether the entire compound has an overall negative or positive charge. If it has an overall negative charge then we would use -ate when naming the compound.
- Sun Dec 06, 2020 7:18 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Ligands
- Replies: 9
- Views: 425
Re: Ligands
So the ligands are essentially the atoms that are attached to rhe central atom. We can calculate the coordination number by looking at the number of ligands (or atoms) that are attached to the central atom.
- Sun Nov 29, 2020 10:34 pm
- Forum: Hybridization
- Topic: Single Bonds and Sigma Bonds
- Replies: 23
- Views: 1046
Re: Single Bonds and Sigma Bonds
Yeah so basically a sigma bond is always present in single, double, and triple bonds.
- Sun Nov 29, 2020 10:32 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Bond Order
- Replies: 14
- Views: 944
Re: Bond Order
If the bond order is zero then that means that the molecule is too unstable and therefore will not create a bond.
- Sun Nov 29, 2020 10:01 pm
- Forum: Hybridization
- Topic: Sapling #12
- Replies: 29
- Views: 961
Re: Sapling #12
When trying to find hybridization you should look at the number of electron dense areas (so bonds and lone pairs). In this problem carbon has 4 single bonds meaning it has 4 electron dense areas and oxygen has 2 single bonds and 2 lone pairs meaning that it also has 4 electron dense areas. This mean...
- Sun Nov 29, 2020 9:47 pm
- Forum: Hybridization
- Topic: e density
- Replies: 30
- Views: 966
Re: e density
Yes electron density is pretty much a section where electrons are pretty much present. So since bonds and lone pairs have electrons they would be denoted as regions of electron density. The more electrons then the higher the electron density.
- Sun Nov 29, 2020 9:43 pm
- Forum: Hybridization
- Topic: Sapling #11
- Replies: 19
- Views: 797
Re: Sapling #11
For these questions make sure to just pay attention to what the question is specifically asking. So here it is specifically talking about P. In the diagram P is bonded to 3 O atoms and it has 1 lone pair. So since there are four regions of electron density then the hybridization is sp3.
- Sun Nov 22, 2020 12:39 pm
- Forum: Coordinate Covalent Bonds
- Topic: Covalent Bond Character
- Replies: 7
- Views: 676
Re: Covalent Bond Character
So essentially Dr. Lavelle was trying to touch up on the fact that ionic bonds form between two ions of opposite charges. So instead of basically sharing electrons as in a covalent bond, ionic bonds happen when an ion essentially is taking an electron from another ion. This force causes the electron...
- Sun Nov 22, 2020 12:27 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Strength in DNA
- Replies: 12
- Views: 688
Re: Bond Strength in DNA
Yeah so since the G-C pair has 3 hydrogen bonds in comparison to A-T which only has 3, G-C pairs would be considered both stronger and more stable. Also, this would explain why G-C pair bonds need higher temperatures to be denatured.
- Sun Nov 22, 2020 12:21 pm
- Forum: Lewis Structures
- Topic: Central Atom Question
- Replies: 20
- Views: 1071
Re: Central Atom Question
H could never be a central atom as it only has one valence electron, meaning that it could only form one bond. Also, central atoms in Lewis structures tend to be those with the lowest ionization energy so keep that in mind when making these structures!
- Sun Nov 22, 2020 12:16 pm
- Forum: Resonance Structures
- Topic: Resonance
- Replies: 11
- Views: 575
Re: Resonance
We want the formal charge of the resonance structures to be as close to 0 as possible. So the structure that provides a formal charge closest to 0 will be considered the most stable.
- Sun Nov 22, 2020 12:08 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: oxidation numbers
- Replies: 4
- Views: 416
Re: oxidation numbers
The oxidation number refers to the number of electrons gained or lost, so it could be a positive, negative, or zero. Basically it helps keep track of electrons in an atom. There a couple of different rules when determining oxidation numbers, for example, the oxidation number of an atom is zero in a ...
- Sun Nov 15, 2020 11:39 pm
- Forum: Ionic & Covalent Bonds
- Topic: polar v nonpolar
- Replies: 7
- Views: 322
Re: polar v nonpolar
Essentially polar bonds form when there are two bonded atoms that an uneven distribution of charges due to an unequal sharing of electrons. Nonpolar bonds form when two atoms have an equal distribution of charges due to an equal sharing of electrons.
- Sun Nov 15, 2020 11:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: Atomic Radius
- Replies: 38
- Views: 2795
Re: Atomic Radius
Yeah so although there are more electrons we must keep in mind that this means that there are also more protons. So, the more protons there are in the nucleus then the more the nucleus pulls on the electrons. This ultimately decreases the radius of the atom.
- Sun Nov 15, 2020 11:06 pm
- Forum: Electronegativity
- Topic: determining electronegativity
- Replies: 40
- Views: 5387
Re: determining electronegativity
We can't necessarily determine an exact value for electronegativity, but what this class wants us to focus on is the period trend. So electronegativity increases when going up and to the right of the periodic table. This would make fluorine the most electronegative element on the table.
- Sun Nov 15, 2020 11:01 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Strengths
- Replies: 10
- Views: 429
Re: Bond Strengths
Yeah I agree with what mostly everyone is saying. The number of bonds has the largest effect on bond strength, followed by atom size, and the finally by the number of lone pairs.
- Sun Nov 15, 2020 10:48 pm
- Forum: Resonance Structures
- Topic: bond length
- Replies: 37
- Views: 1342
Re: bond length
I do not think that we need to know how to calculate bond length necessarily. However, we should definitely be able to differentiate bond length based on the number of bonds. The higher the bond order (single bond, double bond, triple bond), the shorter the bond length.
- Sun Nov 08, 2020 10:41 am
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 987
Re: Hydrogen Bonding
Hydrogen bonding only occurs in molecules where hydrogen is covalently bound to either nitrogen, fluorine, or oxygen. This is because these three elements are extremely electronegative and so are very attracted to hydrogen.
- Sun Nov 08, 2020 10:33 am
- Forum: Ionic & Covalent Bonds
- Topic: Polarity
- Replies: 9
- Views: 428
Re: Polarity
Polarity is similar to characteristics of ionic bonds in the sense that they both describe partial positive and partial negative charges. This means that electrons are shared unequally.
- Sun Nov 08, 2020 10:21 am
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Why is the 4s state filled before the 3d state?
- Replies: 14
- Views: 675
Re: Why is the 4s state filled before the 3d state?
Yeah so to conserve energy, electrons will fill orbital levels that with the lowest energy levels. This is why 4s is filled before 3d.
- Sun Nov 08, 2020 10:14 am
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: Acidosis
- Replies: 3
- Views: 308
Re: Acidosis
Respiratory acidosis essentially is when the lungs can not remove enough of the CO2 produced by the body. The excess amount of CO2 present in the body then causes pH levels of numerous bodily fluids to decrease, leading them to become acidic.
- Sun Nov 08, 2020 10:08 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Stronger acid?
- Replies: 13
- Views: 1116
Re: Stronger acid?
Yeah so since the bond is representative of an oxoacid, determining bond length will not be useful in deducing which acid will be stronger. With oxoacid's we should pay attention to the number of oxygen atoms attached to the central atom. In regards to your question on whether HClO or HClO2 is more ...
- Sun Nov 01, 2020 11:41 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Minimum Uncertainty
- Replies: 3
- Views: 217
Re: Minimum Uncertainty
I am not sure whether this is correct, but I believe that minimum uncertainty is basically the smallest value of "error" that there can be. Like lets say that the uncertainty value given for a certain measurement in a question is 15, we would use 15 to find the minimum uncertainty value. B...
- Sun Nov 01, 2020 11:32 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic vs Ionic Radius
- Replies: 3
- Views: 223
Re: Atomic vs Ionic Radius
Honestly, atomic and ionic radii are pretty similar in what they measure. The main and essentially only difference is that the ionic radius measures the distance from the nucleus to the outermost electrons in a ion while the atomic radius measures the distance from the nucleus to the normal valence ...
- Sun Nov 01, 2020 11:23 pm
- Forum: Ionic & Covalent Bonds
- Topic: Strength of bonds
- Replies: 13
- Views: 548
Re: Strength of bonds
I think that the general order of the strength of bonds is: covalent, ionic, and hydrogen. What I have noticed though is that in some instances people say that ionic bonds are stronger than covalent bonds, but I think this depends on whether the bonds are intramolecular or intermolecular.
- Sun Nov 01, 2020 11:12 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 10
- Views: 550
Re: Electronegativity
The closer an element is to completing their valence shell then the more electronegative they are. This is because they have a stronger tendency of attracting a bonding pair of electrons since they essentially really want to complete their shell.
- Sun Nov 01, 2020 10:57 pm
- Forum: Ionic & Covalent Bonds
- Topic: Is ionic or covalent stronger?
- Replies: 31
- Views: 15147
Re: Is ionic or covalent stronger?
I honestly have found conflicting answers on this question too. From what I remember learning, I think that covalent bonds are generally the strongest. But ionic bonds may be stronger depending on the maximization of the attraction between ions of opposite charges.
- Sun Oct 25, 2020 6:50 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Atomic Orbitals [ENDORSED]
- Replies: 1
- Views: 151
Atomic Orbitals [ENDORSED]
In discussion my TA lightly explained hydrogen wave functions and different atomic orbitals of the electron in a hydrogen atom at different energy levels. When explaining he talked about the different phases and even numbered them in each image of the different atomic orbitals. I'm confused on how w...
- Sun Oct 25, 2020 6:43 pm
- Forum: *Black Body Radiation
- Topic: What is Black Body?
- Replies: 53
- Views: 2109
Re: What is Black Body?
Black body is essentially a surface that absorbs all incident radiation that hits it and, in turn, emits black body radiation. This concept is idealized though since there isn't any surface that is completely black.
- Sun Oct 25, 2020 5:33 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electrons in Orbitals
- Replies: 5
- Views: 155
Re: Electrons in Orbitals
Honestly this is a really good question! It would make sense to just fill up an orbital before moving to the next, however electron's are all negatively charged. Since they are all negatively charged, electrons repel and want to stay far away from one another as possible. To do this, they fill up al...
- Sun Oct 25, 2020 5:17 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity and Electronegativity
- Replies: 9
- Views: 394
Re: Electron Affinity and Electronegativity
Electron affinity basically measures the energy change when a neutral atom attracts an electron to become a negative ion. Electronegativity measures the ability of an atom to attract bonding electrons to itself. One thing to keep in mind though is that both electronegativity and electron affinity in...
- Sun Oct 25, 2020 4:46 pm
- Forum: Properties of Electrons
- Topic: intensity vs energy
- Replies: 29
- Views: 3109
Re: intensity vs energy
The statement is false as an increase in intensity is not associated to an increase in the energy of a photon. By increasing intensity, the only thing changing is the number of photons of light and not the energy of each individual photon. In order to increase the energy of a photon one would have t...
- Sun Oct 18, 2020 11:54 pm
- Forum: Trends in The Periodic Table
- Topic: Period Trends
- Replies: 11
- Views: 475
Re: Period Trends
Those are essentially all of the trends present on the periodic table. The only other ones are the atomic radius and metallic and nonmetallic character. The atomic radius is the measure of the size of an elements atoms. Metallic character refers to the level of reactivity of a metal and non metallic...
- Sun Oct 18, 2020 9:50 pm
- Forum: Properties of Electrons
- Topic: protons and electrons
- Replies: 33
- Views: 2415
Re: protons and electrons
Protons and electrons do not have the same mass. Both protons and neutrons have a much larger mass than electrons. However, protons and neutrons have essentially the same mass. Neutrons are only a little larger in mass than protons, but nothing too major.
- Sun Oct 18, 2020 9:41 pm
- Forum: Properties of Electrons
- Topic: Work function/Threshold Energy
- Replies: 19
- Views: 661
Re: Work function/Threshold Energy
The threshold function and work function are basically the samething. Professor Lavelle was using them almost interchangebly in lecture and I remember writing in my notes that in this scenario they essentially both signify the lowest amount of kinetic energy required to eject an electron.
- Sun Oct 18, 2020 9:32 pm
- Forum: Photoelectric Effect
- Topic: Light Intensity
- Replies: 23
- Views: 403
Re: Light Intensity
Exactly! So the experiment was basically just them changing the intensity of the light, so making it brighter. This is why they noticed that the electrons were not being ejected. However, once they changed the type of light, so the frequency, that is when the electron were ejected.
- Sun Oct 18, 2020 8:56 pm
- Forum: Student Social/Study Group
- Topic: How are you studying?
- Replies: 204
- Views: 16957
Re: How are you studying?
I too am having trouble staying on top of chem. It is incredibly easy to get behind especially since lectures are recorded and the homework is the sundays. But I study by taking notes during lecture and highliting key concepts and terms. I also make sure to look into khan academy videos on math conc...
- Sun Oct 18, 2020 8:56 pm
- Forum: Student Social/Study Group
- Topic: How are you studying?
- Replies: 204
- Views: 16957
Re: How are you studying?
I too am having trouble staying on top of chem. It is incredibly easy to get behind especially since lectures are recorded and the homework is the sundays. But I study by taking notes during lecture and highliting key concepts and terms. I also make sure to look into khan academy videos on math conc...
- Sun Oct 11, 2020 4:19 pm
- Forum: Balancing Chemical Reactions
- Topic: Whole Number Stoichiometric Coefficients
- Replies: 12
- Views: 1432
Re: Whole Number Stoichiometric Coefficients
In lecture Lavelle stated that we need to get rid of fractions as stochiometric coefficients should be whole numbers. So I assume that in the homework, exams, and in general we should make it a habit to convert fractions in chemical equations to whole numbers.
- Sun Oct 11, 2020 4:16 pm
- Forum: Limiting Reactant Calculations
- Topic: Theoretical yield: confused
- Replies: 8
- Views: 554
Re: Theoretical yield: confused
Yeah I completely understand too as I have also been confused on the theoretical and actual yield. So I did some minor research and the theoretical yield is essential the amount of product made if there were no errors made. This is basically impossible though due to side reactions and other things t...
- Sat Oct 10, 2020 11:01 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical and Molecular Formula
- Replies: 17
- Views: 610
Re: Empirical and Molecular Formula
Yes, the empirical and molecular formula can be the same. It essentially depends on the ratio we calculate when determining the empirical formula. For example, if the ratio ends up being 1:1:1 then the empirical formula and the molecular formula will be the same. However, lets say that the empirical...
- Sat Oct 10, 2020 10:55 pm
- Forum: Balancing Chemical Reactions
- Topic: Periodic Table
- Replies: 66
- Views: 4584
Re: Periodic Table
I feel as if though it is highly unlikely that we will need to memorize the periodic table, but we will need to understand how to read a periodic table and acknowledge what the different parts of the periodic table (such as the atomic name, atomic number, atomic symbol, and atomic mass) mean.