Search found 64 matches

by Catly Do 2E
Fri Mar 15, 2019 3:36 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Types of Molecularity
Replies: 4
Views: 207

Re: Types of Molecularity

- Unimolecular reaction: only 1 reactant molecule participates, molecularity =1
- Bimolecular reaction: two reactant species come together to react, molecularity=2
- Termolecular reaction: the collision of 3 molecules & uncommon
by Catly Do 2E
Fri Mar 15, 2019 3:34 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Molecularity
Replies: 3
Views: 161

Re: Molecularity

You can determine molecularity by looking at the number of molecules/ions/atoms that are participating in the rate determining step of a reaction.
by Catly Do 2E
Fri Mar 15, 2019 3:30 pm
Forum: *Enzyme Kinetics
Topic: How do you tell if something is a catalyst vs an intermediate?
Replies: 13
Views: 510

Re: How do you tell if something is a catalyst vs an intermediate?

When you are looking at the elementary reactions, catalysts are in the very first step as a reactant and as a product in the very last step too. Catalysts create a different, faster pathway for the reaction, but it is not used. Intermediates are not present as reactants in the first step but are pro...
by Catly Do 2E
Fri Mar 15, 2019 3:17 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalyst and Activation Energy
Replies: 2
Views: 46

Re: Catalyst and Activation Energy

The catalyst provides a completely different pathway, which speeds up the reaction; it does not speed up the original pathway. You usually base the rate law on the slowest, rate determining step. But when a catalyst is introduced, you can base it upon the new, different pathway the catalyst provides...
by Catly Do 2E
Fri Mar 15, 2019 3:08 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: DeltaS Total
Replies: 2
Views: 206

Re: DeltaS Total

deltaStot = deltaSsys + deltaSsurr
When a reaction is at equilibrium & is reversible.
Then, deltaSsurr=-deltaSsys
by Catly Do 2E
Fri Mar 15, 2019 3:05 pm
Forum: Balancing Redox Reactions
Topic: Balanced Half Reactions
Replies: 5
Views: 180

Re: Balanced Half Reactions

First, focus on balancing the reactants and products of each half reaction. Next, to get the overall reaction, add the two half-reactions together. At this step, you would multiply a factor to a half reaction if needed so that electrons/spectators are canceled as needed for the overall rxn.
by Catly Do 2E
Fri Mar 15, 2019 3:01 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: strong and weak acids
Replies: 5
Views: 245

Re: strong and weak acids

A weak acid has less % dissociation (less of the acid, or the [HA] is breaking down), so that means when you take the pH, the value will be higher.
by Catly Do 2E
Fri Mar 15, 2019 2:58 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Purpose of Arrhenius equation
Replies: 2
Views: 48

Re: Purpose of Arrhenius equation

If we are asked to find the frequency factor, A, it tells us how often molecules collide when the concentration is [1] and whether or not the molecules are properly oriented.
by Catly Do 2E
Fri Mar 15, 2019 2:54 pm
Forum: General Rate Laws
Topic: k'
Replies: 3
Views: 44

Re: k'

Like the others said k' is the rate constant for the reverse reaction. In addition to applying it to the K=k/k', you can also see k' in elementary reaction rates that are used to find net rate of formation.
by Catly Do 2E
Mon Mar 11, 2019 7:20 pm
Forum: Experimental Details
Topic: Dimerization
Replies: 2
Views: 175

Re: Dimerization

I think dimerization is referring to an addition reaction where two molecules of the same compound react. For example, molecule A + molecule A reacts to form molecule A2.
by Catly Do 2E
Mon Mar 11, 2019 7:16 pm
Forum: Balancing Redox Reactions
Topic: Oxidation number?
Replies: 12
Views: 200

Re: Oxidation number?

This list really helped me determined oxidation numbers!
by Catly Do 2E
Mon Feb 25, 2019 2:45 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge vs porous disk
Replies: 2
Views: 44

Re: salt bridge vs porous disk

Both the salt bridge and the porous disk have the same purpose in a cell. They facilitate ion transfer, which stops charge buildup within the cell. I don't think we have to know when/why either is used for this class; it will be either be stated in the problem or it won't be significant.
by Catly Do 2E
Mon Feb 25, 2019 2:38 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic vs Voltaic
Replies: 1
Views: 32

Re: Galvanic vs Voltaic

They are the same; there are just two names for it. Both are names for an electrochemical cell in which a spontaneous redox reaction is induced to create electrical charge flow.
by Catly Do 2E
Mon Feb 25, 2019 2:34 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: F in Nernst Equation
Replies: 2
Views: 47

Re: F in Nernst Equation

Yes, F is the Faraday constant. The Faraday constant represents the # of colombs per mole of elections. I think it is given to us on the equation sheet!
by Catly Do 2E
Sun Feb 17, 2019 2:41 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Entropy using statefunctions
Replies: 2
Views: 207

Re: Entropy using statefunctions

Because entropy is a state function, it doesn't matter what "path" you take, as long as you correctly get from point A to point B. Therefore, you calculate the change in volume, then you can calculate the change in temperature (or vice versa, it doesn't what order you do it in). Then you a...
by Catly Do 2E
Sun Feb 17, 2019 2:38 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Monatomic VS Diatomic Gases and their C
Replies: 3
Views: 211

Re: Monatomic VS Diatomic Gases and their C

They are different because their C value is different depending on the structure of the molecule you're looking at and whether or not the system is at constant pressure or constant volume. Cv,m=3/2R for a monatomic molecule Cv,m= 5/2R for a diatomic or linear molecule Cp,m=5/2R for a monatomic molec...
by Catly Do 2E
Sun Feb 17, 2019 2:35 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: calculating delta S
Replies: 4
Views: 58

Re: calculating delta S

Using the ideal gas law, or Boyle's law, where PV=nRT, P and V are inversely proportional which is why V2/V1=P1/P2.
by Catly Do 2E
Thu Feb 07, 2019 12:15 am
Forum: Calculating Work of Expansion
Topic: Different Work Equations
Replies: 2
Views: 65

Re: Different Work Equations

Le learned this in discussion today and these are from my notes!
- For a reversible, isothermal expansion of an ideal gas:
w=-nRTln(Vfinal/Vinitial) OR w=-nRTln(Pinitial/Pfinal)
- For constant pressure:
w=-PdeltaV=-deltanRT
- For constant volume:
w=0
by Catly Do 2E
Wed Feb 06, 2019 11:52 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 'C' constant
Replies: 2
Views: 49

Re: 'C' constant

The constant C in (ΔS = nC ln (T2/T1)) stands for the heat capacity at constant volume or constant pressure, depending on the problem.
by Catly Do 2E
Wed Feb 06, 2019 11:36 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Degeneracy
Replies: 2
Views: 37

Re: Degeneracy

Degeneracy refers to the multiple ways that energy can be configured. Entropy refers to the "uncertainty" or "disorder" of a system. They have a proportional relationship; as degeneracy increases, entropy increases too, vice versa.
by Catly Do 2E
Wed Feb 06, 2019 11:31 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Negative q
Replies: 7
Views: 111

Re: Negative q

Heat (q) is negative when the amount of heat is being released/reaction is exothermic. The equation for entropy includes delta q, or the change in q; this is how q and entropy are related.
by Catly Do 2E
Wed Feb 06, 2019 11:27 pm
Forum: Calculating Work of Expansion
Topic: 6th edition 8.31
Replies: 3
Views: 72

Re: 6th edition 8.31

Here's the worked out problem!
by Catly Do 2E
Wed Feb 06, 2019 10:20 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temp affecting K
Replies: 4
Views: 103

Re: Temp affecting K

Temperature is the only thing that affects the equilibrium constant (K). Therefore, when temperature changes, so does K. Q is used to calculate the current state or a hypothetical state of a reaction to compare to the K for the temperature to see whether the reaction will favor reactants or products.
by Catly Do 2E
Wed Feb 06, 2019 10:17 pm
Forum: Student Social/Study Group
Topic: Unit Conversion for Temp
Replies: 2
Views: 57

Re: Unit Conversion for Temp

We don't have to always convert to K for every calculation in chemistry, but most of the equations we use right now have units that use K in them. The best course of action is to look at the units used in the equation/problem and adjust accordingly.
by Catly Do 2E
Tue Feb 05, 2019 3:03 pm
Forum: Calculating Work of Expansion
Topic: Reversible and Irreversible Reactions
Replies: 2
Views: 50

Re: Reversible and Irreversible Reactions

More work is down in a reversible expansion because they move very slowly and work against external pressure. Think about the equations; the equation for reversible expansion uses an integral for accuracy because the expansion is slower and does more work whereas the equation for irreversible equati...
by Catly Do 2E
Tue Feb 05, 2019 2:44 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Microstate
Replies: 7
Views: 161

Re: Microstate

Microstates are specific ways in which the energy of a system can be arranged. The multiple ways the energy can be arranged depends on the atom/molecule arrangements. Entropy is the measure of uncertainty in a system, so the more microstates there are, the higher the entropy.
by Catly Do 2E
Tue Feb 05, 2019 12:32 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy
Replies: 2
Views: 57

Re: Entropy

DeltaU describes the change in internal energy of a system and DeltaH describes the change in total heat content of the system. Entropy is the measure of uncertainty, which is very significant in describing a system.
by Catly Do 2E
Mon Feb 04, 2019 2:05 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Thermos
Replies: 4
Views: 73

Re: Thermos

A thermos is technically an isolated system because there is no exchange of matter or energy between the system (thermos) and surroundings. However, a cold or hot drink in the thermos will eventually get to room temperature. It's very difficult to achieve and build a true, isolated system, but the t...
by Catly Do 2E
Sun Feb 03, 2019 11:44 pm
Forum: Phase Changes & Related Calculations
Topic: Heating Curve
Replies: 4
Views: 69

Re: Heating Curve

Steam hurts a lot more than just hot water because of the energy difference. Looking at the heating curve, steam (water in gas form) lies higher than hot water (water in liquid form; although it is hot water and "holds" more energy, it is still a liquid). When the steam hits your hand, the...
by Catly Do 2E
Sun Feb 03, 2019 11:39 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: intensive vs extensive properties
Replies: 2
Views: 63

Re: intensive vs extensive properties

Extensive properties depend on the quantity of material being measured. An example of an extensive property is mass. The higher the quantity of the material, the higher the mass will be. On the other hand, intensive properties don't depend on the quantity of material being measured. For example, an ...
by Catly Do 2E
Sun Feb 03, 2019 11:36 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Hess's Law depends on enthalpy as a state function
Replies: 3
Views: 69

Re: Hess's Law depends on enthalpy as a state function

Hess's Law states that the heat of a specific reaction is equal to the sum of the heats of reaction. This depends on the fact that enthalpy is a state function because state function values do not depend on the path that is taken to reach that specific value. Therefore, it is okay to add/subtract th...
by Catly Do 2E
Sun Feb 03, 2019 11:27 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated systems
Replies: 2
Views: 47

Re: Isolated systems

Isolated systems are important because there is no energy or matter transfer between the system and its surroundings. An open system allows both energy and matter to transfer between the system and its surroundings & a closed system allows energy to be transferred between the system and its surr...
by Catly Do 2E
Thu Dec 06, 2018 2:49 pm
Forum: Ionic & Covalent Bonds
Topic: Net dipole
Replies: 2
Views: 101

Re: Net dipole

ClF3 is T-Shaped, and so the dipole movement between the Cl and F atoms do not evenly cancel each other out. This means the ClF3 molecule is polar. However, the BF3 molecule is trigonal planar, so the dipole movement between the B and F atoms cancel each other out. The dipole movement points to the ...
by Catly Do 2E
Thu Dec 06, 2018 2:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing trigonal planar
Replies: 4
Views: 82

Re: Drawing trigonal planar

You don't have to draw wedges/lined triangles in a trigonal planar shape. The wedges and such indicate that the bond is 3D (either "coming out" of the paper or "going into" the paper), but all four atoms in a trigonal planar molecule lay flat.
by Catly Do 2E
Thu Dec 06, 2018 2:43 pm
Forum: Student Social/Study Group
Topic: Dec 5 Notes
Replies: 2
Views: 273

Re: Dec 5 Notes

Here!
by Catly Do 2E
Thu Dec 06, 2018 2:31 pm
Forum: Conjugate Acids & Bases
Topic: Inverse Proportional
Replies: 2
Views: 91

Re: Inverse Proportional

Yes, the relationship between the strength of an acid/base and the strength of its conjugate base/acid is inversely proportional. The stronger the base is, the stronger its conjugate acid & vice versa.
by Catly Do 2E
Thu Dec 06, 2018 2:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AX3E
Replies: 18
Views: 299

Re: AX3E

First, add together the number of bonds in the molecule (the number following X). In this case, it is 3. Then add the number of lone pairs (the number following E). In this case, it is 1. 3 + 1 = 4. Therefore, we know that the shape is tetrahedral, but since there is a lone pair, the geometry is tri...
by Catly Do 2E
Thu Dec 06, 2018 2:20 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Water
Replies: 2
Views: 59

Re: Water

When we increase the temperature, water's ability to ionize increases, so [H+] increases, which means pH decreases. Essentially, a record of a pH value without a corresponding temperature value is not enough information in something like a lab report. If it is just water by itself, I don't think tem...
by Catly Do 2E
Thu Dec 06, 2018 2:10 pm
Forum: Identifying Acidic & Basic Salts
Topic: Neutral salt
Replies: 3
Views: 201

Re: Neutral salt

Looking at salt as the product of an acid-base reaction, we can determine how the salt would act. For example, a popular neutral salt is table salt, or NaCl. We know the Na+ ion comes from NaOH. NaOH is a strong base, dissociating fully. Once dissociated, Na+ does not want to turn back into NaOH. We...
by Catly Do 2E
Thu Dec 06, 2018 2:01 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka equation
Replies: 2
Views: 81

Re: Ka equation

Water is left out of the equation because it doesn't change in concentration. These equations are determining the strength of an acid/base, so the constant H2O concentration does not play a role.
by Catly Do 2E
Thu Dec 06, 2018 1:50 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pH
Replies: 2
Views: 61

Re: Calculating pH

For example, we are given that the molarity of a solution is 0.1M NaOH. Since we know that NaOH is a strong base, we know that it will fully dissociate. Therefore,
0.1 M NaOH --> 0.1 M OH-
pH = 14 - pOH = 14 - (-log([OH-])) = 14 - (-log([0.1M)) = 14 - 1 = 13

So, the final answer is pH = 13.
by Catly Do 2E
Thu Dec 06, 2018 1:44 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: PKa and Pkb vs Ka and Kb
Replies: 4
Views: 442

Re: PKa and Pkb vs Ka and Kb

They aren't exactly the same, but they are related. The PKa/PKb is used to measure the strength of an acid or base in solution whereas pH is specifically the measure of the concentration of hydrogen ions in solution.
by Catly Do 2E
Thu Dec 06, 2018 1:41 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Acid/Base
Replies: 3
Views: 77

Re: Conjugate Acid/Base

In an acid-base reaction, the conjugate acid/base are on the products side of the equation. Essentially, the conjugate acid is the base with a hydrogen ion added to it. The conjugate base what is remaining after the original acid has donated a proton during the acid-base reaction.
by Catly Do 2E
Sat Nov 17, 2018 9:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity
Replies: 3
Views: 56

Re: Polarity

Polar compounds are often nonsymmetrical as well. The lack of symmetry is what causes dipole moments. Nonpolar molecules do not have dipole moments because either the bonded atoms do not have a great enough electronegativity difference or the molecule is symmetrical and the dipole moments cancel.
by Catly Do 2E
Sat Nov 17, 2018 9:00 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: Lewis Structures before Forces
Replies: 3
Views: 98

Re: Lewis Structures before Forces

I agree with the others who have responded. I feel that it is always best to start out with a Lewis structure and then go from there. You can determine the shape/structure and then observe how the intermolecular forces affect molecule interaction.
by Catly Do 2E
Sat Nov 17, 2018 8:48 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: Energy of Intermolecular Forces
Replies: 6
Views: 145

Re: Energy of Intermolecular Forces

It seems a little bit counterintuitive, but forming bonds requires energy. Creating a bond is bringing 2+ atoms into a more stable position. Thus, breaking the bond is where energy is absorbed whereas forming bonds is where energy is released.
by Catly Do 2E
Sat Nov 17, 2018 8:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.17d
Replies: 2
Views: 43

Re: 4.17d

Determining when the bond angle is a "little less" or "slightly less" greatly depends on the existence of lone pairs and how it creates repulsion against one another and thus, against the other atoms within the molecules. I like to try to imagine the molecule and picture how cert...
by Catly Do 2E
Sat Nov 17, 2018 8:36 pm
Forum: Bond Lengths & Energies
Topic: 6th edition 3.87
Replies: 2
Views: 70

Re: 6th edition 3.87

Essentially, the question is asking the following: Of CF4, CCl4, and CBr4, which is the strongest bond? The strongest bond would be the shortest bond; the pull between the two atoms is the strongest. Therefore, the strongest C-X bond would be predicted to be CF4.
by Catly Do 2E
Sat Nov 17, 2018 8:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 16
Views: 222

Re: Bond Angles

It isn't necessary to memorize exact bond angles for specific molecules. Dr. Lavelle mentioned that we just need to know how lone pairs affect repulsion and nearby bond angles (i.e. a lone pair will push against adjacent bond angles, making them less than the standard degree for that specific shape).
by Catly Do 2E
Sun Nov 04, 2018 6:11 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 4
Views: 96

Re: Electronegativity

Electronegativity is how efficient an atom can attract electrons and electron affinity is the energy released when an electron is added in the gaseous state to form an anion. Electronegativity increases and electron affinity gets more negative from left to right, and from bottom to top.
by Catly Do 2E
Sun Nov 04, 2018 5:40 pm
Forum: Trends in The Periodic Table
Topic: Atomic Radius
Replies: 4
Views: 97

Re: Atomic Radius

An easy way to memorize how the atomic radius trends are to consider how electrons and protons are attracted to each other.
by Catly Do 2E
Sun Nov 04, 2018 5:36 pm
Forum: Ionic & Covalent Bonds
Topic: Naming Ionic Compounds
Replies: 5
Views: 86

Re: Naming Ionic Compounds

I don't think Dr. Lavelle said anything specific about naming ionic compounds, but an easy way to remember is to name the cation first and then name the anion second, changing the suffix of the nonmetal to "-ide."
by Catly Do 2E
Mon Oct 29, 2018 3:04 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Balmer series, Lyman series?
Replies: 3
Views: 120

Re: Balmer series, Lyman series?

The Balmer and Lyman series are just named for series with a specific final resting energy quanta level (n). Lyman's final resting spot is n=1 whereas Balmer ends at n=2.
by Catly Do 2E
Mon Oct 29, 2018 2:42 am
Forum: Ionic & Covalent Bonds
Topic: Roman numerals next to element
Replies: 8
Views: 434

Re: Roman numerals next to element

The use of Roman numerals in chemical nomenclature is to indicate the charge of the ion. Usually, the transitional metal has multiple possible ion charges. For example, Fe (II) stands for Fe2+ and Fe (III) stands for Fe3+; the charge changes according to the number of electrons on the atom.
by Catly Do 2E
Mon Oct 29, 2018 2:39 am
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 13
Views: 134

Re: Lewis Structures

The center atom is most likely the one with the lowest ionization/electronization energy.
by Catly Do 2E
Mon Oct 22, 2018 8:48 pm
Forum: Lewis Structures
Topic: determining shapes of molecules
Replies: 2
Views: 124

Re: determining shapes of molecules

When determining the shape of a molecule, I like to draw a basic Lewis dot structure model and then use the VSEPR (Valence Shell Electron Pair Repulsion) theory, which states that the repulsion of the valence electron pairs is what gives the molecules their shape.
by Catly Do 2E
Mon Oct 22, 2018 8:44 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Pauli Exclusion Principle
Replies: 3
Views: 65

Re: Pauli Exclusion Principle

Essentially the Pauli exclusion principle doesn't allow the electrons to have the same exact quantum numbers. So to occupy the same orbital, the spin has to be different.
by Catly Do 2E
Mon Oct 22, 2018 8:27 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Two exceptions
Replies: 2
Views: 39

Re: Two exceptions

There are two exceptions because a completely full/half full d sub-level is more stable than when partially filled, so an electron from the 4 oribital is excited and moves to a 3d orbital. They are more stable configurations. And I agree, I think we should memorize these exceptions.
by Catly Do 2E
Sun Oct 14, 2018 2:54 pm
Forum: Significant Figures
Topic: When to round the answers to significant figures
Replies: 11
Views: 477

Re: When to round the answers to significant figures

I usually try to keep as many sig figs as I can during the calculations so that the final answer is more accurate. Then, I do all the rounding and cut down to the appropriate number of sig figs at the final step.
by Catly Do 2E
Fri Oct 12, 2018 6:38 pm
Forum: DeBroglie Equation
Topic: "Wave-like Properties" of Matter
Replies: 6
Views: 83

Re: "Wave-like Properties" of Matter

I think Dr. Lavelle mentioned this in lecture! From what I remember, he said there is no specific wavelength where a moving object is considered to have "measurable wave-like properties." I don't think we will have to worry about this on any tests/quizzes though, it's just something to kee...
by Catly Do 2E
Fri Oct 12, 2018 6:23 pm
Forum: Properties of Light
Topic: 6th Edition Ch.1 #57
Replies: 1
Views: 37

6th Edition Ch.1 #57

Can someone explain how to do Ch.1 6th edition 57?
by Catly Do 2E
Thu Oct 04, 2018 5:31 pm
Forum: Empirical & Molecular Formulas
Topic: HW 1 Problem F.9
Replies: 7
Views: 115

Re: HW 1 Problem F.9

Yes, they are asking for the empirical formula.
by Catly Do 2E
Thu Oct 04, 2018 5:25 pm
Forum: SI Units, Unit Conversions
Topic: Homework: E1, 6th Ed.
Replies: 5
Views: 143

Re: Homework: E1, 6th Ed.

It gives you the radius, but you need the diameter to get the length of the chain. So 2 x 144 pm = 288 pm. 1 mol of Ag means there are 6.022 x 10^23 atoms of Ag. Then you multiply (6.022 x 10^23 atoms of Ag)(288 pm)= 1.73 x 10^26 pm. Then, you convert to km, which is 1.73 x 10^11 km.
by Catly Do 2E
Thu Oct 04, 2018 5:01 pm
Forum: Significant Figures
Topic: Sig Figs
Replies: 6
Views: 134

Re: Sig Figs

Whenever there is a decimal, you count from left to right starting with the first nonzero number, which is why 400.0 and 400.00 have a different amount of sig figs.

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