Search found 59 matches

by Tam To 1B
Tue Feb 19, 2019 7:06 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4I.9
Replies: 2
Views: 14

Re: 4I.9

Remember that in a reversible reaction, any small change in a variable, such as pressure, of the system will cause a similar change in the surroundings so that there is essentially no change in internal energy. ( U = 0 ) Because in part b the pathway is irreversible, this means that any change in va...
by Tam To 1B
Tue Feb 19, 2019 12:05 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Concentration and free energy
Replies: 2
Views: 10

Concentration and free energy

Does changing the concentration of a substance in a reaction affect the free energy?
by Tam To 1B
Tue Feb 19, 2019 11:03 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Relationship between enthalpy, entropy, and Gibbs
Replies: 4
Views: 17

Relationship between enthalpy, entropy, and Gibbs

How does free energy change with temperature when the value of enthalpy is negative and entropy is negative?
How does free energy change with temperature when the value of enthalpy is positive and entropy is positive?
by Tam To 1B
Mon Feb 11, 2019 10:23 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Question 8.39 (Sixth Edition)
Replies: 4
Views: 34

Re: Question 8.39 (Sixth Edition)

For this problem, you have to calculate the enthalpy of fusion (ice melting) and the heat of the water to determine how much needs to be supplied in total. The enthalpy of fusion, delta H, can be calculated using the value from table 8.3. Convert 80.0 g H20 to moles and multiply it with the enthalpy...
by Tam To 1B
Mon Feb 11, 2019 10:09 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Question 8.19 (Sixth Edition)
Replies: 3
Views: 25

Re: Question 8.19 (Sixth Edition)

So with this question, you want to find q of both the copper and the water and add it together to find the total amount of heat supplied. You know that q = mCdeltaT q(copper) = (500 g)(0.38 J/gC)(100-22 C) = 14.82 kJ q(water) = (400 g)(4.184 J/gC)(100-22 C) = 130.54 kJ q(total) = 14.82 + 130.54 = 14...
by Tam To 1B
Mon Feb 11, 2019 10:03 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 12.55 part b 6th edition
Replies: 1
Views: 17

Re: 12.55 part b 6th edition

You should plug it in as -0.3+√(0.3^2 - 4(1)(-0.6)) and divide it all by 2. You should get a positive number inside the square root and x = 0.137.
by Tam To 1B
Tue Feb 05, 2019 4:44 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Equipartition Theorem
Replies: 1
Views: 19

Equipartition Theorem

Are we required to know the equipartition theorem?
I'm also confused about the translational, rotational linear, and rotational nonlinear equations that go along with it.
by Tam To 1B
Mon Feb 04, 2019 10:26 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 8.41 6th edition
Replies: 2
Views: 34

Re: 8.41 6th edition

In this problem, you add the enthalpy of fusion, heat absorbed by ice, and heat released by water. In order to find the enthalpy of fusion, you convert 50.0 g H20(s) to mol and multiply it by the enthalpy of fusion. This would be 2.775 mol H20 * 6.01E3 J/mol (convert kJ in textbook to J). The heat a...
by Tam To 1B
Mon Feb 04, 2019 10:15 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Open vs Closed Systems
Replies: 4
Views: 29

Re: Open vs Closed Systems

An open system is one in which matter and energy can exchange with the surroundings. A closed system is one in which only energy can exchange with the surroundings. An isolated system is one in which nothing can exchange with the surroundings. For example, an open system can just be a cup of hot wat...
by Tam To 1B
Mon Feb 04, 2019 10:04 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpy
Replies: 2
Views: 13

Re: Bond Enthalpy

I'm assuming mostly like no. We learned lewis structures in 14A so I think they expect you to be able to know which bonds would be broken or formed.
by Tam To 1B
Tue Jan 29, 2019 10:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Kekulé Structures
Replies: 1
Views: 34

Re: Kekulé Structures

For this problem, they are just asking you to compare the differences between the bond enthalpies of benzene. In one structure, you have benzene with 3 C-C and 3 C=C bonds. Using the table, this would mean (3*348) + (3*612) = 2880 kJ. However, benzene in its resonance structure has 6 C-C/C=C bonds (...
by Tam To 1B
Tue Jan 29, 2019 11:26 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Sig Figs with Enthalpy
Replies: 4
Views: 21

Sig Figs with Enthalpy

Do we apply the rules of sig figs when calculating enthalpy?
by Tam To 1B
Tue Jan 29, 2019 11:24 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat and work
Replies: 4
Views: 22

Heat and work

What is the difference between heat and work? How do they relate to internal energy?
by Tam To 1B
Tue Jan 22, 2019 11:18 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.3 7th Edition (When to use P vs molecular formula/concentrations)
Replies: 5
Views: 16

Re: 5G.3 7th Edition (When to use P vs molecular formula/concentrations)

The solution is just writing out the chemical equilibrium constant in the form of Kp rather than Kc. They are interchangeable for gases only. When writing it with P subscripts, this indicates that it is Kp, with the equilibrium partial pressures of products on top divided by the equilibrium partial ...
by Tam To 1B
Tue Jan 22, 2019 10:22 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature change
Replies: 5
Views: 40

Re: Temperature change

The increase in temperature depends on whether the reaction is exothermic or endothermic. If a reaction is endothermic, an increase in temperature will make it proceed to the right and produce more products. This means the reverse reaction is exothermic, so a decrease in temperature will make it pro...
by Tam To 1B
Tue Jan 22, 2019 10:16 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test and acid/ base recognition
Replies: 1
Views: 30

Re: Test and acid/ base recognition

From Chem 14A, we had to memorize which acids were strong and what categorized bases as strong. Strong acids: HCl, HI, HBr, H2SO4, HNO3, HClO4 Strong bases: Most of Group 1 and 2 metal hydroxides If you know those, then everything else should be a weak acid or base. However, I would assume in the qu...
by Tam To 1B
Thu Jan 17, 2019 10:47 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Hemoglobin and Homeostasis
Replies: 1
Views: 23

Hemoglobin and Homeostasis

How does partial pressure and concentration of oxygen affect hemoglobin and oxygen exchange?
by Tam To 1B
Tue Jan 15, 2019 2:00 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Part 4 Post-Module Question
Replies: 4
Views: 25

Re: Part 4 Post-Module Question

In this problem, we are taking into account of exothermic and endothermic reactions. The reaction shifts toward the endothermic reaction. If a reaction is endothermic, it will have a positive delta H, meaning that increasing temperature will favor the forward reaction and product formation. If a rea...
by Tam To 1B
Tue Jan 15, 2019 1:54 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: positive vs. negative delta H
Replies: 2
Views: 18

Re: positive vs. negative delta H

Delta H basically means the change in enthalpy, or in other words, the change in "heat". When delta H is positive, it means the products in the reaction have more energy compared to the reactants, so the reaction has gained energy, making it endothermic. When delta H is negative, it means ...
by Tam To 1B
Tue Jan 15, 2019 1:50 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Hmwrk 11.41 6th edition
Replies: 1
Views: 26

Re: Hmwrk 11.41 6th edition

The answer is 1.58E-8. In order to do this problem you convert 17.4 mg CO2 to moles and divide by 0.250 L to get the equilibrium molarity concentration of CO2, 1.58E-3. Since NH4(NH2CO2) is a solid, it's not included in the equilibrium constant, so you have K = [NH3]^2[CO2]. Because you have two mol...
by Tam To 1B
Thu Jan 10, 2019 11:09 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Help with question 11.43 6th edition [ENDORSED]
Replies: 2
Views: 33

Re: Help with question 11.43 6th edition [ENDORSED]

On the ICE table, you have to find initial molar concentration, change in molar concentration, and the equilibrium molar concentration. Since you are initially given 1.0 mol/L NO, the change would be -2x since you have the coefficient 2NO in the reaction. In order to calculate equilibrium, you subtr...
by Tam To 1B
Wed Jan 09, 2019 9:47 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6th Edition 11.45
Replies: 1
Views: 33

6th Edition 11.45

Hello! I'm stuck on question 11.45 part b. (a) A sample of 2.0 mmol Cl2 was sealed into a 2.0 L reaction vessel and heated to 1000. K to study its dissociation into Cl atoms. Use the info in Table 11.2 to calculate the equilibrium composition of the mixture. (b) If 2.0 mmol F2 was placed into the re...
by Tam To 1B
Wed Jan 09, 2019 5:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.9 Hmwrk 6th edition
Replies: 1
Views: 25

Re: 11.9 Hmwrk 6th edition

Yes; since you aren't given any numerical equilibrium molar concentrations, the question just asks for you to set it up.
So basically it would be Kc = [products]/[reactants] raised to the power of their stoichiometric coefficients.
by Tam To 1B
Mon Dec 03, 2018 4:39 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 6th Edition 17.37
Replies: 2
Views: 30

Re: 6th Edition 17.37

For (c), en is a bidentate, so it has two binding sites. (en)2 = 4 binding sites total + 2 binding Cl = 6 ligands total, so the coordination number is 6. For (d), edta is a hexadentate, so it has six binding sites, making the coordination number for Cr to be 6. More info can be found in section 17.6...
by Tam To 1B
Mon Dec 03, 2018 3:47 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ch.17-#31b (6th edition) Coordination Compounds
Replies: 2
Views: 30

Re: Ch.17-#31b (6th edition) Coordination Compounds

Yes, ligands should be written in alphabetical order, ignoring the prefix that indicates the number of each one present.
For example, in that particular compound, "ammine" comes before "sulfato" in alphabetical order, so NH3 is written first.
by Tam To 1B
Mon Dec 03, 2018 3:12 pm
Forum: Naming
Topic: Prefix bis, tris, tetrakis, etc. [ENDORSED]
Replies: 5
Views: 101

Prefix bis, tris, tetrakis, etc. [ENDORSED]

Hello!

I'm a little confused as to when we name coordination compounds with bis, tris, tetrakis, etc.
What's an example of when this is used instead of di, tri, tetra, etc.?

Thank you!
by Tam To 1B
Sun Dec 02, 2018 1:14 pm
Forum: Lewis Acids & Bases
Topic: 6th Edition 12.15
Replies: 1
Views: 27

6th Edition 12.15

Hello! Question 12.15 in the 6th edition asks to write the Lewis structure of each reactant, identify the Lewis acid and the Lewis base, and then write the Lewis structure of the product for the following acid-base reaction: (b) Cl- + SO2 --> I'm a little confused on this one, because I thought SO2 ...
by Tam To 1B
Mon Nov 26, 2018 10:00 am
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Water as a solvent
Replies: 2
Views: 33

Re: Water as a solvent

Water has a bent shape and this makes it a universal solvent because the positive and negative ends are furthest from each other. Since the H atoms give off a positive charge and oxygen gives off a negative charge, molecules of either charge are able to attract to water. Water's polar covalent chara...
by Tam To 1B
Mon Nov 26, 2018 9:48 am
Forum: Hybridization
Topic: Hybridization with Lone Pairs
Replies: 4
Views: 23

Re: Hybridization with Lone Pairs

Yes, in this case N would be sp3 hybridized. When a lone pair of electrons are localized, they are considered in hybrid orbitals.
However, in the case of resonance structures, delocalized electrons in the resonance structures are not counted in hybrid orbitals.
by Tam To 1B
Mon Nov 26, 2018 9:45 am
Forum: Bond Lengths & Energies
Topic: Covalent Bond Dissociation Energy
Replies: 2
Views: 35

Covalent Bond Dissociation Energy

What exactly is covalent bond dissociation energy and how does it relate to atomic radius, bond multiplicity, and lone pairs in bonding?
by Tam To 1B
Tue Nov 20, 2018 2:10 pm
Forum: Electronegativity
Topic: Electronegativity and Polarity
Replies: 3
Views: 36

Electronegativity and Polarity

What's the relation between polarizability and electronegativity?
by Tam To 1B
Tue Nov 20, 2018 1:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs
Replies: 4
Views: 31

Re: lone pairs

I believe lone pairs on non central atoms would affect the polarity of the molecule and create a dipole, but it shouldn't affect the overall shape of the molecule. For example, with CH2F2 has a tetrahedral shape. However, F has lone pairs. This would just mean that the molecule is polar, but the sha...
by Tam To 1B
Tue Nov 20, 2018 1:38 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Hund's rule vs Pauli's
Replies: 3
Views: 55

Re: Hund's rule vs Pauli's

Hund's rule states that one electron must fill each orbital first with a parallel spin before it can fill up with two electrons in each orbital with opposite spins. For example, in a 2p orbital, one electron must fill each 2px1, 2py1, 2pz1, before another electron can fill those orbitals. The Paul E...
by Tam To 1B
Tue Nov 13, 2018 10:07 pm
Forum: Dipole Moments
Topic: Induced-dipole
Replies: 5
Views: 52

Re: Induced-dipole

Dipoles are unequal pulls of electrons. Induced-dipoles happen in London dispersion forces. What happens is that in an atom with an equal amount of electrons dispersed around, a temporary dipole force can occur. For instance, some electrons can temporarily shift to one side, causing one side of the ...
by Tam To 1B
Tue Nov 13, 2018 5:52 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Stable Vs. Formal
Replies: 4
Views: 83

Re: Stable Vs. Formal

Formal charge would refer to the charge of each individual atom and the overall number of electrons an atom owns in a molecule. I believe stable charge would just be the most stable form of the entire molecule.
by Tam To 1B
Tue Nov 13, 2018 5:35 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 6
Views: 97

Re: Resonance Structures

Resonance is a blending of structures. For example, a nitrate ion lewis structure depicts N as the central atom with bonds to three O atoms. Nitrate has one double bond and two single bonds. The double bond is connected to an oxygen, however, it can be connected to any of the three O atoms. This mak...
by Tam To 1B
Thu Nov 08, 2018 2:42 pm
Forum: Ionic & Covalent Bonds
Topic: Chemical formula from compound name
Replies: 2
Views: 30

Re: Chemical formula from compound name

The Roman numerals indicate the charge. For example, this means that Indium has a 3+ charge. We know that sulfur has a 2- charge, so the compound would be made of 2 Indium and 3 Sulfur to cancel out to charges. This results in the chemical formula: In2S3.
by Tam To 1B
Thu Nov 08, 2018 2:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW for discussion
Replies: 9
Views: 142

Re: HW for discussion

The homework we turn in should correspond to what we've learned in class recently from the past week.
by Tam To 1B
Tue Nov 06, 2018 1:27 pm
Forum: Octet Exceptions
Topic: Central atoms with more than 8 electrons
Replies: 3
Views: 56

Re: Central atoms with more than 8 electrons

Elements such as P or S do have open d-orbitals. This is because they have 3s and 3p orbitals already and have available 3d orbitals that can be filled next, allowing them to break the octet rule and have expanded valence shells. On the other hand, this wouldn't work for elements before period 3, be...
by Tam To 1B
Tue Oct 30, 2018 12:54 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Stable Structure in SO4^-2
Replies: 1
Views: 51

Re: Stable Structure in SO4^-2

You might be mixing up FC with the overall charge of the ion. I think he said when the formal charge equals 0, that's when it's most stable. In both lewis structures he drew of the sulfate ion, they both resulted in having the -2 charge of the ion. In the first structure with single bonds, each oxyg...
by Tam To 1B
Mon Oct 29, 2018 11:09 pm
Forum: Ionic & Covalent Bonds
Topic: 6th edition 3.9 and 3.11
Replies: 1
Views: 24

Re: 6th edition 3.9 and 3.11

These questions are basically asking which metal ions with a 2+ charge would have the electron configuration given? The 2+ charge means that 2 electrons were taken away to get the positive charge. For instance, 3.9a) [Ar]3d^7 Add back 2 electrons to get [Ar]3d^7, 4s^2. (Remember 4s fills up before 3...
by Tam To 1B
Mon Oct 29, 2018 11:03 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: How to write electron config for Bi3+?
Replies: 1
Views: 21

Re: How to write electron config for Bi3+?

Xenon's electron configuration is [Kr]4d^10, 5s^2, 5p^6. The ground state electron configuration for Bi is [Xe]4f^14, 5d^10, 6s^2, 6p^3 because you have to continue off that sequence. The 4f^14 and 5d^10 are from period 6 Lanthanoids and transition metals. It may not show as a single row on the PT, ...
by Tam To 1B
Wed Oct 24, 2018 9:18 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: #28 Atomic Spectroscopy Post-Assessment for module
Replies: 1
Views: 43

Re: #28 Atomic Spectroscopy Post-Assessment for module

What I did was that since it says "the meter" was defined as 1650763.73 wavelengths, I divided 1 meter / 1650763.73 wavelengths. I think this should get you one wavelength.
by Tam To 1B
Tue Oct 23, 2018 2:34 pm
Forum: Properties of Light
Topic: Is light in waves or photons?
Replies: 10
Views: 189

Re: Is light in waves or photons?

Light has both wave and photon properties. Wave properties of light explain the inverse relationship between wavelength and frequency of light. It also explains how amplitude represents the intensity of the wave. In this case, bigger amplitude (more intensity light) means greater energy. Meanwhile, ...
by Tam To 1B
Tue Oct 23, 2018 11:52 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: differences in equation
Replies: 2
Views: 46

Re: differences in equation

I think in the textbook the h has a line through it. This is a different h value that equals h/(2pi). That's why the h/2 is still equal to h/(4pi). The equation is the same; the notation of the h just makes it appear different.
by Tam To 1B
Tue Oct 23, 2018 10:53 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Series and Wavelengths part 2
Replies: 1
Views: 34

Re: Series and Wavelengths part 2

The Balmer series has lines with n(1) = 2 and n(2) > 2. It consists of lines that go from n = 2 as well as value anything above that as the second n value. So we know: 656.3 is n = 3 --> n = 2 486.1 is n = 4 --> n = 2 434.0 is n = 5 --> n = 2 410.2 is n = 6 --> n = 2 So now the next one would be : ?...
by Tam To 1B
Mon Oct 15, 2018 10:37 pm
Forum: DeBroglie Equation
Topic: Wavelength question 1.57 (6th edition)
Replies: 1
Views: 32

Re: Wavelength question 1.57 (6th edition)

So you know that the equation for the hydrogen spectrum is En = -hR/n^2. where R = 3.29E15 Hz. In this case you know that the Balmer series is where there is a transition from any energy level greater than 2 to n = 2. So 656.3 is n = 3 --> n = 2, 486.1 is n = 4 --> n = 2, 434.0 is n = 5 --> n = 2, 4...
by Tam To 1B
Mon Oct 15, 2018 6:04 pm
Forum: Properties of Light
Topic: When is the midterm?
Replies: 1
Views: 56

Re: When is the midterm?

The midterm is Monday, November 5, 6-8pm.
It's on his site under "test and exam schedule"
https://lavelle.chem.ucla.edu/wp-conten ... hedule.pdf
by Tam To 1B
Mon Oct 15, 2018 4:55 pm
Forum: Photoelectric Effect
Topic: HW Question 1.33
Replies: 1
Views: 38

Re: HW Question 1.33

Part c asks you to find the wavelength of the energy of the photon. In this case, you would use the equation E(photon) - work function = E(kinetic energy), where E(photon) = work function + E(kinetic energy). So from part b you should have found the work function to be 1.66E-17 J. Convert the given ...
by Tam To 1B
Mon Oct 15, 2018 4:41 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Question 1.15 sixth edition
Replies: 10
Views: 108

Re: Question 1.15 sixth edition

First, I think you mean that the frequency you got is 2.92E15 Hz (s^-1) On page 7 of Section 1.3, there is a figure that shows 102.6 nm is part of the Lyman series, which is on n = 1, so you know that the first energy level is n = 1. In order to find what it transitions to, you can use the equation ...
by Tam To 1B
Thu Oct 11, 2018 11:58 am
Forum: DeBroglie Equation
Topic: Homework Question 1.37 6th Ed
Replies: 2
Views: 31

Re: Homework Question 1.37 6th Ed

I think this question is meant to show that their wavelengths are basically going to be the same. Since they are so close in size, there is very little difference, so you can say they are almost identical.
by Tam To 1B
Tue Oct 09, 2018 9:27 pm
Forum: Photoelectric Effect
Topic: Post-Mod Problem #28
Replies: 4
Views: 42

Re: Post-Mod Problem #28

The mass of an electron is always about 9.11E-31 kg.
by Tam To 1B
Tue Oct 09, 2018 4:40 pm
Forum: Photoelectric Effect
Topic: Work Function, Kinetic Energy
Replies: 2
Views: 68

Re: Work Function, Kinetic Energy

E(kinetic energy of e-) = .5mv^2.
The mass of the electron will usually be given to you.
The mass of an electron is about 9.11E-31 kg. Plug it in and you should get your answer!
by Tam To 1B
Tue Oct 09, 2018 4:33 pm
Forum: Photoelectric Effect
Topic: Post-Mod Problem #28
Replies: 4
Views: 42

Re: Post-Mod Problem #28

You know that E(photon) - E(energy to remove e-) = E(kinetic energy of e-). You also know that E(photon) = h(planck's constant) x v (frequency) In other words, hv - work function = (1/2)mv^2 (where m = mass of e- and v = velocity of e-) Mass of e- = 9.11E-31, Given velocity = 6.61E5 This would then ...
by Tam To 1B
Tue Oct 09, 2018 1:43 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect and Experiment
Replies: 2
Views: 28

Re: Photoelectric Effect and Experiment

In the photoelectric experiment, light was shone on a metal surface. If the energy of the incoming light was greater than the energy needed to remove the electron (work function), then electrons were emitted from the surface. This way, we are able to measure their kinetic energy.(Ephoton - Ework fun...
by Tam To 1B
Tue Oct 02, 2018 5:07 pm
Forum: Molarity, Solutions, Dilutions
Topic: Titrations v Dilutions
Replies: 2
Views: 52

Re: Titrations v Dilutions

Titrations are when you measure the volume of one solution and see how much you need for it to react with the volume of another solution. For example, think of acid-base titrations. You know the amount of volume of the acid in a flask, but you don't know how much base is needed to react and neutrali...
by Tam To 1B
Tue Oct 02, 2018 4:52 pm
Forum: Molarity, Solutions, Dilutions
Topic: Find concentration of ions given more than one solute
Replies: 2
Views: 33

Re: Find concentration of ions given more than one solute

1. First you would determine the amount of moles for KCl, K2S, and K3PO4 by dividing the mass given by the molar mass of each compound. In that case, you would get 0.00671 mol KCl, 0.004535 mol K2S, and 0.00236 mol K3PO4. 2. In order to calculate the amount of potassium ions, you would take into acc...
by Tam To 1B
Tue Oct 02, 2018 4:32 pm
Forum: Significant Figures
Topic: Significant Figures
Replies: 6
Views: 81

Re: Significant Figures

When you do sig figs for addition/subtraction, only think about the amount of digits after the decimal point. First you would do addition/subtraction normally, then afterwards you would round your answer to the least number of places in the decimal portion of the numbers you added/subtracted. For ex...

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