## Search found 65 matches

Fri Mar 15, 2019 3:05 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalyst and Activation Energy
Replies: 2
Views: 127

### Catalyst and Activation Energy

We learned in class that a catalyst serves to provide a new pathway for the reaction mechanism to go through to produce the products faster. However some sources say that a catalyst can't be described as lowering the activation energy, instead providing a different pathway with a lower activation en...
Mon Mar 11, 2019 10:08 am
Forum: First Order Reactions
Topic: 7B.9
Replies: 3
Views: 140

### Re: 7B.9

Essentially the equation is just finding the change from initial [A(initial)] to find the value of [A] after a point in the reaction. Since we know the initial concentration of the product [B] is 0, the formation concentration of it can be treated as a decomposition of [A] if we multiply by the mole...
Mon Mar 11, 2019 10:03 am
Forum: General Rate Laws
Topic: Order of rxns and stoichiometric coefficients
Replies: 3
Views: 124

### Re: Order of rxns and stoichiometric coefficients

They can coincidentally be the same value, but we can't set the order of reaction based off stoichiometric coefficients. It takes some work, but calculating and determining the order from the experimental data is the best and only way to get the right order.
Mon Mar 11, 2019 10:01 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: HW 15.27
Replies: 3
Views: 351

### Re: HW 15.27

To start, you can use the half life for first order reaction like you said in order to find the rate constant k. Then, you can use another equation that describes the behavior of the reaction summed over time and plug in k and use ratios to find the value of t. You can also use a sample initial conc...
Mon Mar 11, 2019 9:56 am
Forum: Second Order Reactions
Topic: Graphs of second order
Replies: 1
Views: 118

### Re: Graphs of second order

The graph of a 2nd reaction is graphed on the axes of (x = time) and (y = 1/[concentration]). In order to visualize our reaction in a linear format, we consider it in terms of 1/[Molarity]. This is similar to how we take the natural log of the concentration for the 1st order reaction to get a line. ...
Mon Mar 04, 2019 2:58 pm
Forum: First Order Reactions
Topic: Dividing Experiments to Find Order
Replies: 4
Views: 167

### Re: Dividing Experiments to Find Order

Trying to keep it in terms of ratios can help to figure out the exponent values easier. If we need to reduce the coefficients a bit in order to do so can help as well, but in essence nothing should specifically change.
Mon Mar 04, 2019 2:56 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: how is kinetics different?
Replies: 17
Views: 684

### Re: how is kinetics different?

Another aspect of kinetics is that we're considering rates (derivatives), which become time and activity dependent. This helps to give a context in exactly what we're analyzing in terms of the reaction. In thermodynamics, we didn't particularly study any rates of activity.
Mon Mar 04, 2019 2:53 pm
Forum: General Rate Laws
Topic: 1st and 2nd order
Replies: 6
Views: 286

### Re: 1st and 2nd order

In addition to using data tables, it can also be determined through the usage of graphs as the example we saw today. In applying a ln(x) function to the concentration function, we can potentially determine whether it's a first or different order reaction. However, experimentally calculating it is of...
Mon Feb 25, 2019 10:29 am
Forum: Balancing Redox Reactions
Topic: Rules for redox reactions
Replies: 3
Views: 121

### Re: Rules for redox reactions

There aren't really "rules" for redox reactions, but they make use of the typical oxidation states of the elements. When calculating the charge changes, we won't be given them in the question. Instead, we'll easily be able to find them from the periodic table, or memory as we've used these...
Mon Feb 25, 2019 10:26 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous and unstable
Replies: 4
Views: 423

### Re: Spontaneous and unstable

Our spontaneity can help us to conceptually understand what stability means. In essence; the spontaneous reaction which increases the entropy of the universe is most favored. This can be considered a value of stability, as the reaction ends up being universally favorable. The opposite reaction would...
Mon Feb 25, 2019 10:21 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: When to use Platinum
Replies: 5
Views: 499

### Re: When to use Platinum

Using an inert electrode (most often Pt) allows the half of the cell to facilitate reduction/oxidation when the solution is fully aqueous. Electrons will be transferrable on the surface of the electrode. If the electrode is involved in the half cell with the solution (solid copper and aqueous), then...
Mon Feb 25, 2019 10:17 am
Forum: Balancing Redox Reactions
Topic: Salt Bridges-won't they dissolve?
Replies: 5
Views: 202

### Re: Salt Bridges-won't they dissolve?

The salt bridge essentially helps to prevent charge accumulation on either side (which would nullify the battery system). Since it is made out of tubing with gel, it will not chemically interact with the cell. It allows the charges to move, and to keep the cell going.
Mon Feb 18, 2019 4:21 pm
Forum: Van't Hoff Equation
Topic: Concept behind Van't Hoff Equation
Replies: 5
Views: 228

### Re: Concept behind Van't Hoff Equation

It helps to relate the effect of temperature on the equilibrium constant of a reaction. Back when we were looking at Le Chatelier's principle, we noticed that only a change in temperature changed our equilibrium constant as a whole, and this equation can be used to see how a change in temperature di...
Mon Feb 18, 2019 4:18 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G
Replies: 3
Views: 135

### Re: Delta G

Exergonic: (-) sign. It releases energy spontaneously, which fits our definition for a negative delta G value. The bonds formed are essentially stronger than the bonds broken. Endergonic: (+) sign. It absorbs energy, which fits the definition of the positive delta G value, being not spontaneous at a...
Mon Feb 18, 2019 4:12 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy
Replies: 5
Views: 185

### Re: Gibbs Free Energy

To start understanding what our free energy means, we can look at the equation of delta G = delta H - Temp*(delta S). Our delta H (enthalpy) value is in joules or kilojoules, and multiplying our entropy value times the temperature of the reaction will give us a value in joules as well. So, we can se...
Mon Feb 11, 2019 10:11 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Statistical vs Residual Entropy
Replies: 4
Views: 192

### Re: Statistical vs Residual Entropy

I think that the statements above are correct, as a large error in W (degeneracy) constitutes a small error in the residual entropy. It seems that the residual entropy is flexible to the errors in W. But, as always it doesn't count the thermal entropy we can calculate using the same equation.
Mon Feb 11, 2019 9:56 am
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy Change in reversible reaction
Replies: 3
Views: 141

### Re: Entropy Change in reversible reaction

In addition to the responses above, we can see that entropy would not be 0 in any cases as it violates the laws of thermodynamics, where entropy only approaches 0 when it's at ~0 K. (Third Law). In an isothermal system our temperature is constant, so it doesn't approach 0. (Only delta T is 0). When ...
Mon Feb 11, 2019 9:46 am
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: Degeneracy
Replies: 4
Views: 173

### Re: Degeneracy

In addition to the responses above, it's important to draw the structures for the molecules we are considering, as it can help us to see what the resonance structures are and to total the amount of equal energy states (or positions) that we have. From this information it'll allow us to determine deg...
Mon Feb 04, 2019 10:00 am
Forum: Calculating Work of Expansion
Topic: Work sign changes
Replies: 3
Views: 156

### Re: Work sign changes

When the system is expanding, the volume will be a positive value, ultimately making the work value negative. When it's compressed, the volume will be a negative value, which makes the work in total a positive value. So, when the system does work, it is negative. When work is done on the system, it'...
Mon Feb 04, 2019 9:48 am
Forum: Calculating Work of Expansion
Topic: Integral calculations
Replies: 4
Views: 200

### Re: Integral calculations

Since our integral is of integral of P with respect to dV, we are integrating a constant. So our difference is of the difference of V, which is why we aren't necessarily taking an *actual* integral. In essence, we are doing the integral through using the formula of -P* delta V. (This is all based of...
Mon Feb 04, 2019 9:45 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 3 methods for enthalpy calculation
Replies: 10
Views: 520

### Re: 3 methods for enthalpy calculation

If we are given the actual steps for each part of the reaction, then that is the most accurate way to find the enthalpy for the reaction (Hess's Law). Then, from the enthalpies of formation we would be able to get another method of finding the total enthalpy, but it would not be as accurate since it...
Mon Jan 28, 2019 10:03 am
Forum: Phase Changes & Related Calculations
Topic: Enthalpy signs
Replies: 13
Views: 438

### Re: Enthalpy signs

Another aspect of this is thinking of the heat as a product or reactant, where in an endothermic reaction (+) it would require heat which can be considered as a reactant. In an exothermic reaction (-), where heat is given off, we can think of it as a product.
Mon Jan 28, 2019 9:58 am
Forum: Phase Changes & Related Calculations
Topic: State properties
Replies: 3
Views: 117

### Re: State properties

The example of altitude in the lecture from last week is a good example, as for a state function we just see the initial and final and compare it regardless of the path take (the two teams traveled a total different amount of distance but ended up in the same point of altitude). However in terms of ...
Mon Jan 28, 2019 9:55 am
Forum: Phase Changes & Related Calculations
Topic: Different enthalpy calculation methods
Replies: 4
Views: 135

### Re: Different enthalpy calculation methods

I think it depends on what information we are given for the calculation. If we are given something with a step by step enthalpy for each step, we could use Hess's method, but if we aren't given the enthalpies for each step of the total reaction then we might decide on using the bond enthalpies to su...
Sat Jan 19, 2019 4:23 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Replies: 4
Views: 164

When an inert gas is added to the system, it doesn't participate in the reaction at all, and the reacting gases will retain their same volume and remain unchanged. That's why when we have inert gases we can pretty much disregard it.
Sat Jan 19, 2019 4:19 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changes in K
Replies: 4
Views: 168

### Re: Changes in K

Temperature (as said above) is the only change that will have an effect on the K constant. This is due to a change in energy provided and other conditions related to temperature change. Often raising the temperature will shift it to endothermic direction.
Sat Jan 19, 2019 4:15 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle and Partial Pressure
Replies: 3
Views: 106

### Re: Le Chatelier's Principle and Partial Pressure

Le Chatelier's principle tries to explain how the system will try to reduce the stress put on it. If the system loses pressure or (loss of concentration) on one side, the system can push towards the reverse (or whichever direction) it requires in order to equalize. In this case, it'll reduce on the ...
Sat Jan 12, 2019 10:58 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: "quick" way to solve changes in pressure
Replies: 3
Views: 127

### Re: "quick" way to solve changes in pressure

It's a way to estimate how the moles factor in to the pressure of each part of the system, a "quick" way to understand which direction it'll go. But overall it'll help to check logically each step.
Sat Jan 12, 2019 10:55 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: doubling pressure
Replies: 2
Views: 97

### Re: doubling pressure

In addition to the reply above, it is a strong example of how the principle works to rebalance the system (pushing the equilibrium to either direction).
Sat Jan 12, 2019 10:48 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: pressure and temperature
Replies: 4
Views: 47

### Re: pressure and temperature

Since the K constant is a ratio of concentrations and the temperature change does affect the K constant's value, I think it would make sense that the concentrations would shift accordingly to reflect the change in ratio.
Wed Jan 09, 2019 8:16 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: 11.13c (6th Edition)
Replies: 2
Views: 107

### Re: 11.13c (6th Edition)

I believe the partial pressure will be used in terms of when all (or possible most) the products or reactants are in the gas phase.
Wed Jan 09, 2019 8:14 pm
Forum: Ideal Gases
Topic: Reaction Quotient
Replies: 4
Views: 156

### Re: Reaction Quotient

The reaction quotient also may not always match with the equilibrium constant, which should also be checked for when doing the problem. It'll probably come up later on in the quarter.
Wed Jan 09, 2019 8:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating the Equilibrium Composition in ATP Hydrolysis
Replies: 4
Views: 109

### Re: Calculating the Equilibrium Composition in ATP Hydrolysis

One of the reasons Dr Lavelle subtracted the value of the equilibrium value from the initial value was to determine the change in molarity. Since the values were 0 for the others (ADP and Pi), and the equation was balanced with coefficients of 1, we were able to understand the change was equal to th...
Mon Dec 03, 2018 8:36 pm
Forum: Biological Examples
Topic: cisplatin in stopping DNA replication
Replies: 3
Views: 172

### Re: cisplatin in stopping DNA replication

In addition to the posts above, since it is a cis version of the molecule, it is also a polar molecule since the Cl groups (x2) face opposite of the NH3 groups (x2), which can be thought to let it have unique properties compared to the trans version where it would be nonpolar.
Mon Dec 03, 2018 8:32 pm
Forum: Bronsted Acids & Bases
Topic: Calculations Involving Strong Acid (or Base)
Replies: 3
Views: 114

### Re: Calculations Involving Strong Acid (or Base)

Strong acids and bases are ones that deprotonate or protonate almost fully in water solutions, and they're the ones I think he said we will mostly use in this class (with exceptions). For calculation we can treat a strong base like KOH in whatever concentration as equal to the OH ion concentration, ...
Mon Dec 03, 2018 8:29 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Acids and Bases
Replies: 2
Views: 193

### Re: Bronsted Acids and Bases

Bronsted Acids and Bases don't really go beyond that definition as it's a proton-centric model of how we can understand acid and base compounds. Proton donation and accepting are characteristics of acids and bases in this definition and that is how we can analyze in a reaction what our acid and base...
Mon Nov 26, 2018 2:34 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: linear vs bent question
Replies: 7
Views: 307

### Re: linear vs bent question

In addition to the great explanations above, the lone pairs become very important in differentiating certain compound models due to their repulsive forces, which also directly changes the bond angles. They are tricky but important for understanding the compounds better.
Mon Nov 26, 2018 2:33 pm
Forum: Biological Examples
Topic: Chelating compounds
Replies: 2
Views: 63

### Re: Chelating compounds

The chelating compounds have to do with the ligands involved around the metal ion in the center, which forms the rings characteristic of a chelating compound. The reason certain ligands allow the development of the chelating compound has to do with what types of bonds can be formed from those compou...
Mon Nov 26, 2018 2:29 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: labeling hybridization
Replies: 3
Views: 130

### Re: labeling hybridization

One way to do it is since we are labelling the hybridization starting from B to F, we would identify the shape of the atom based on VSEPR (for example Trigonal Planar), then relate the corresponding hybridized orientation value. There is a good table in the book than can help to identify it.
Sun Nov 18, 2018 8:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Model formation
Replies: 2
Views: 99

### Re: Model formation

It wouldn't correspond to a different model in total, but the angles can differ based on which atoms are present and their relative forces of electronic repulsion.
Sun Nov 18, 2018 8:47 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 4
Views: 189

### Re: Molecular Shape

Shape of molecules acts as a big character of the compound, especially in biological systems where form equals function and other principles can determine the reactivity and action. For example, certain prion diseases can be from benign ones unfolding or folding in a different state, causing lethal ...
Sun Nov 18, 2018 8:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles Less Than a Certain Value
Replies: 4
Views: 186

### Re: Angles Less Than a Certain Value

Often we can answer the less than values by determining the differences in repulsion compared to other examples of the same orientation, where greater repulsive force from a pair or atom will push the others accordingly. It depends on each unique compound.
Mon Nov 12, 2018 2:41 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths [ENDORSED]
Replies: 3
Views: 211

### Re: Bond lengths[ENDORSED]

The number of electrons in an atom do not necessarily determine bond strength, but the electrons involved in the bond do. For example, with more electron involvement in a triple bond, the atoms need to be closer to each other with a greater attraction in order to facilitate more covalent bonding. Be...
Mon Nov 12, 2018 2:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: determining VSEPR models
Replies: 6
Views: 248

### Re: determining VSEPR models

In addition to the responses above: what helps to form our VSEPR models is to be aware of the lone pairs in the model, which will cause repulsion and push the atoms into specific shapes. Even if our number of atoms are the same across different models, it is very possible to have different VSEPR str...
Mon Nov 12, 2018 2:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 2E.1
Replies: 2
Views: 63

### Re: 2E.1

Since it shows a structure that isn't fully linear, we can deduce that there must be some sort of electron density on the central atom that is causing repulsion of the other atoms joined to the central atom. Therefore, we can be sure there is a lone pair causing repulsion, "bending" the sh...
Fri Nov 09, 2018 2:46 pm
Forum: Bond Lengths & Energies
Topic: 2D.3 (7th ed)
Replies: 2
Views: 82

### Re: 2D.3 (7th ed)

In addition to the response above, the way we can tell the character of the bond has thresholds around 1.5, where less than that it will be covalent while greater it can be ionic character. There's a very nice diagram in that section that graphs out some specific examples and the character identific...
Fri Nov 09, 2018 2:43 pm
Forum: Dipole Moments
Topic: Attractive Force
Replies: 3
Views: 64

### Re: Attractive Force

I think depending on the energy levels and ultimately the distance between each atom, the bond can be weaker even if the size is larger. But, it ultimately becomes the ratios between distance and energy level that will determine the attractiveness.
Fri Nov 09, 2018 2:40 pm
Forum: Dipole Moments
Topic: H bond
Replies: 1
Views: 84

### Re: H bond

Since the bond in the H2O atom is a single covalent bond between Oxygen and Hydrogen and the Hydrogen bond between two water molecules is due to lone pair pull, they exhibit different levels of attraction. A covalent bond is a true physical sharing and distortion of the electron cloud between the mo...
Mon Oct 29, 2018 9:11 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Finding Formal Charge
Replies: 3
Views: 131

### Re: Finding Formal Charge

Another aspect of finding the formal charge and its usefulness comes from being able to understand the overall charge of the ion, which we should be able to derive by calculating charges of the individual atoms. This can help when we have an ion that we are not sure of what the exact charge is, but ...
Mon Oct 29, 2018 3:44 pm
Forum: Resonance Structures
Topic: Bond lengths
Replies: 6
Views: 133

### Re: Bond lengths

The experimentally observed bond lengths were shown in lecture to probably display how our model cannot fully grasp the true nature of the molecule's arrangement, as we have to find an average to find the true length and arrangement. A double bond is shorter than a single bond, but it does not mean ...
Mon Oct 29, 2018 3:41 pm
Forum: Lewis Structures
Topic: Lines that Represent Bonds
Replies: 7
Views: 256

### Re: Lines that Represent Bonds

As said above either is fine, but lines are useful in counting the electrons and also being able to keep track of charges when calculating formal charges as well. This continues in to the fact that when we come to resonance structures it makes it easier to visualize the different electron placements...
Mon Oct 29, 2018 3:36 pm
Forum: Ionic & Covalent Bonds
Topic: Lewis Dot Structures: Ionization Energy
Replies: 6
Views: 262

### Re: Lewis Dot Structures: Ionization Energy

Since it has the lowest ionization energy, you can think of it in terms of is it more willing to gain or lose an electron (become an ion) or to ultimately share or gain the electron in a bond. C is generally a "backbone" for structures because it is direct in the middle with 4 valence elec...
Tue Oct 23, 2018 8:33 pm
Forum: *Shrodinger Equation
Topic: What is probability density?
Replies: 2
Views: 1016

### Re: What is probability density?

There is a slight difference between psi and psi^2, which helps to understand Schrodinger's Equation conceptually. Psi itself is a wavefunction, which varies with position. Once we square this value it becomes only positive, and provides a dimensional model of the area we can probabilistically find ...
Tue Oct 23, 2018 8:27 pm
Forum: Photoelectric Effect
Topic: Example 1.5 6th edition
Replies: 2
Views: 188

### Re: Example 1.5 6th edition

I think we should be able to convert the values if needed (same as any unit based question). The conversion value is on the sheet so we should be just fine if the question is presented in eVs.
Tue Oct 23, 2018 8:25 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron density?
Replies: 4
Views: 70

### Re: Electron density?

It helps to understand how the wave functions (psi) in Schrodinger's equation are a mathematical representation of where electrons may be found. When we square psi to find the probability density, we are essentially able to understand which regions there is a greater probability of finding an electr...
Mon Oct 15, 2018 4:02 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Absorption/Emission
Replies: 4
Views: 135

### Re: Absorption/Emission

Absorption and Emission are two aspects of how energy is transferred among particles and compounds. For example in reactions energy is absorbed to make bonds, while emitted when breaking. In particles we see light from the excitement of electrons, where energy is absorbed when excited, and given off...
Mon Oct 15, 2018 3:50 pm
Forum: *Shrodinger Equation
Topic: Wavefunction
Replies: 3
Views: 212

### Re: Wavefunction

I think for the purpose of the class and for learning about the "Quantum World", knowing the Schrodinger Wave Function Equation is essential for a conceptual understanding. From my understanding the equation allows us to gain a probable location of the particle (probability density) by sol...
Mon Oct 15, 2018 3:37 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Heisenberg
Replies: 5
Views: 193

### Re: Heisenberg

It is the principle that (in addition to the fact that on an atomic level measurement influences outcome) we cannot accurately define both the momentum and position of a particle at the same time. For example, we can estimate a probable area of where the electron may be in an atom, but we would be u...
Tue Oct 09, 2018 6:14 pm
Forum: Properties of Light
Topic: C=Delta x V
Replies: 6
Views: 232

### Re: C=Delta x V

Using this equation (C= Lambda x V) we can analyze specific waves of light against the constant that is the speed of light, so we can glean some information on its wavelength, frequency, and additionally from that where it belongs on the electromagnetic spectrum. It's a type of linear equation that ...
Tue Oct 09, 2018 6:11 pm
Forum: Properties of Light
Topic: Light
Replies: 5
Views: 276

### Re: Light

I had this question too and still do, but I have come to some understanding that our model for light is still debated on. In a large scale sense, our wave model of light works for our use in physics and larger chemistry, however when coming down to particle side such unique phenomena where intensity...
Tue Oct 09, 2018 6:07 pm
Forum: Properties of Light
Topic: Difference between "intensity of light" and "frequency of light"
Replies: 3
Views: 1324

### Re: Difference between "intensity of light" and "frequency of light"

Thanks for the clarification up there, it is very helpful. I found this interesting because it helps to glean some insight on the importance of "quanta" in the particle model of light, where increasing the intensity of light will by no means change the energy in the photons. If it is alrea...
Thu Oct 04, 2018 11:20 am
Forum: Empirical & Molecular Formulas
Topic: Empirical Formula
Replies: 6
Views: 283

### Re: Empirical Formula

When we have percentages for elemental composition, it makes it much easier to determine the grams in the sample (especially if we do not have a sample given), then we can use molar masses to determine the moles and the empirical formula. In essence, it makes it much easier to glean important inform...
Tue Oct 02, 2018 4:00 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Isotopes [ENDORSED]
Replies: 12
Views: 794

### Re: Isotopes[ENDORSED]

Another interesting fact that can help conceptualize the importance of isotopes is that the molar mass of the atoms we have on the Periodic Table are in fact representative of the most commonly (or long-lasting) isotope of the atom we can observe. These will definitely be important as we get to deep...
Tue Oct 02, 2018 3:57 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Moles!
Replies: 7
Views: 250

### Re: Moles!

Definitely check out videos regarding concepts of moles and matter, but I can try to give a short description. A mole is the concept of a certain amount of a compound or element, usually defined by Avogadro's number (6.022*10^23), which tells us about how many particles (atoms, molecules) of whateve...
Tue Oct 02, 2018 3:45 pm
Forum: Balancing Chemical Reactions
Topic: States of Matter
Replies: 11
Views: 754

### Re: States of Matter

Since aqueous solutions have been discussed already, the most important thing about keeping track of states of matter during balancing equations is to get familiar with certain reaction patterns and probable products that may be formed. For combustion (for example) knowing the fact O2 gas is a fuel ...