## Search found 34 matches

Thu Jul 25, 2019 6:13 pm
Forum: Naming
Topic: Fe------ferrate? [ENDORSED]
Replies: 8
Views: 734

### Re: Fe------ferrate?[ENDORSED]

1) Cyanido and cyano are interchangeable. So if the ligand is a negative charge, you can end it in -o or -ido. 2) Since the overall charge is negative, the metal always has to end in -ate. But, it's not "ironate", it's ferrate (the latin name). Similarly, the metal copper becomes cuprate i...
Thu Jul 25, 2019 6:05 pm
Forum: Bronsted Acids & Bases
Topic: finding initial molarity hw 12.25
Replies: 2
Views: 345

### Re: finding initial molarity hw 12.25

No ICE tables will be used since we never went over it in class. First, you would write out the chemical reaction of Ba(OH)2 and balance it in order to see the moles of each product and reactant. Next, since we are trying to find the molarity, you need to convert grams of Ba(OH)2 to moles. Next, you...
Wed Jul 24, 2019 11:15 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework Problem 4.1
Replies: 2
Views: 331

### Re: Homework Problem 4.1

What about the example of (CH2)2-. This molecule has a lewis structure of two single bonds of the hydrogen atom coming off of the central carbon atom along with two lone pairs of electrons on the carbon. What shape and bond angles would this result in? Can a linear molecule have only 3 lone pairs in...
Wed Jul 24, 2019 12:43 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework Problem 4.1
Replies: 2
Views: 331

### Homework Problem 4.1

4.1: Below are ball-and-stick models of two molecules. In each case, indicate whether there must be, may be, or cannot be one or more lone pairs of electrons on the central atom. For this problem, I was confused about part b which shows a model of a linear molecule with a 180 degree bond angle. The ...
Wed Jul 24, 2019 12:36 am
Forum: Hybridization
Topic: Homework Problem 4.95
Replies: 1
Views: 254

### Homework Problem 4.95

4.95: Consider the bonding in CH2£CHCHO. (a) Draw the most important Lewis structure. Include all nonzero formal charges. (b) Identify the composition of the bonds and the hybridization of each lone pair—for example, by writing (H1s,C2sp2). I understand how to draw out the Lewis structure for this p...
Mon Jul 22, 2019 10:57 pm
Forum: Hybridization
Topic: Homework Problem 4.43
Replies: 1
Views: 256

### Homework Problem 4.43

4.43: Noting that the bond angle of an sp3 hybridized atom is 109.5 and that of an sp2 hybridized atom is 120 , do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased? The solutions manual says that as the s-character increases...
Mon Jul 22, 2019 10:48 pm
Forum: Hybridization
Topic: dsp3 vs. sp3d
Replies: 3
Views: 341

### dsp3 vs. sp3d

4.35 Identify the hybrid orbitals used by the atom in boldface type in each of the following species: (c) BrF3 I got the answer for this problem to be dsp3 since the lewis structure comes out to be a trigonal bipyramidal. However, the solutions manual shows that it is sp3d. Is one correct over the o...
Sat Jul 20, 2019 6:10 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Which do you prioritize first
Replies: 10
Views: 697

### Re: Which do you prioritize first

You always prioritize the number of valence electrons first. Counting the valence electrons is what allows you to draw out a rough sketch of the Lewis structure for that molecule. Formal charge comes into play last, when you're trying to figure out if what you have drawn is the best representation o...
Sat Jul 20, 2019 6:06 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizing Power [ENDORSED]
Replies: 8
Views: 777

### Re: Polarizing Power[ENDORSED]

Polarizability is defined as the ability for a cation to distort an anion. As the atomic radius of an atom increases, the polarizing power decreases. As the atomic radius of an atom decreases, the polarizing power increases. Also, the greater the charge on an atom, the higher the polarizing power.
Sat Jul 20, 2019 4:34 pm
Forum: Lewis Structures
Topic: Problem 2B3 7th Edition
Replies: 2
Views: 365

### Re: Problem 2B3 7th Edition

When trying to find the best lewis structure possible, you always have to account for the formal charge. The first possibility is to have two single bonded Si-O. The formal charge for each silicon and oxygen atom would come out as 2 and -1, respectively. The second possibility is to have two doubled...
Sat Jul 20, 2019 4:25 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: name of molecule structure
Replies: 4
Views: 528

### Re: name of molecule structure

When drawn out, sulfur tetrachloride has 4 single bonds of S-Cl coming off of sulfur. After accounting for the octet rule, you get 32 electrons, but you need 34. So, a lone pair is added to the sulfur atom. Thus, the molecule has 5 regions of electron density (4 single bonds and 1 lone pair). This p...
Sat Jul 20, 2019 4:15 pm
Forum: Bond Lengths & Energies
Topic: Intermolecular vs. Intramolecular forces
Replies: 5
Views: 457

### Re: Intermolecular vs. Intramolecular forces

Intermolecular forces are forces that occur between two or more molecules/compounds. Intramolecular forces are forces that occur within a molecule, or in other words between two atoms of a molecule/compound. For example, in a group of H20 molecules, intermolecular forces occur when the hydrogen atom...
Sat Jul 20, 2019 3:55 pm
Forum: Ionic & Covalent Bonds
Topic: Notation of electron configurations of ions
Replies: 5
Views: 1184

### Re: Notation of electron configurations of ions

The electron configuration for As is [Ar]3d104s24p3. As3+ means that 3 electrons have been removed. When you're writing the electron configuration for As3+, you remove electrons from the valence shell. In this case, you remove electrons from the 4p orbital. Thus, you get [Ar]3d104s2. You cannot just...
Sat Jul 20, 2019 3:43 pm
Forum: Sigma & Pi Bonds
Topic: Hybrid Orbitals [ENDORSED]
Replies: 1
Views: 361

### Hybrid Orbitals[ENDORSED]

What exactly is the significance of hybrid orbitals? Why do we use them?
Tue Jul 16, 2019 11:19 pm
Forum: Ionic & Covalent Bonds
Replies: 7
Views: 650

What is molecular orbital theory?
Sat Jul 13, 2019 4:01 pm
Forum: Ionic & Covalent Bonds
Replies: 7
Views: 650

How exactly do radicals form and how would we know if we are given a radical? Are there specific elements that are more likely to form radicals? And how would you go about the process of drawing a radical?
Sat Jul 13, 2019 3:56 pm
Forum: Bond Lengths & Energies
Topic: Electrostatic Potential Energy Formula
Replies: 2
Views: 315

### Electrostatic Potential Energy Formula

I'm a little confused about the following equation: [(q1)(q2)]/r

I know that q1 and q2 represent charges and that r represents distance between charges, but I'm not exactly sure what this formula represents. Can someone help me understand the significance of it?
Fri Jul 12, 2019 7:34 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizability vs. Polarizing Power
Replies: 3
Views: 294

### Polarizability vs. Polarizing Power

In discussion section we talked about two different periodic trends polarizability and polarizing power. What exactly are the differences between the two trends?
Fri Jul 12, 2019 7:25 pm
Forum: Ionic & Covalent Bonds
Topic: Ground State
Replies: 13
Views: 850

### Re: Ground State

Remember that copper is one of the exceptions for electron configuration, along with Chromium. Copper has an electron configuration of [Ar]3d^(10)4s^(1) in its normal state. For the copper Cu+ ion, the electron configuration is [Ar]3d^(10). This is because electrons are removed from the 4s orbital b...
Thu Jul 11, 2019 9:50 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 6
Views: 482

### Formal Charge

Can someone explain what exactly formal charge is, and what is the purpose of calculating it? Why is it most favorable for formal charge to be between -1 and 1?
Mon Jul 08, 2019 12:33 am
Forum: Properties of Electrons
Topic: Wave Properties of Electrons- Module Question
Replies: 3
Views: 415

### Wave Properties of Electrons- Module Question

In some experiments electrons display particle-like properties and in other experiments electrons display wave-like properties. True or false? The answer is True for this question, but I'm not sure why. I thought electrons only display wave-like properties based on the diffraction patterns. Can some...
Sat Jul 06, 2019 9:14 pm
Forum: Photoelectric Effect
Topic: Calculating Kinetic Energy
Replies: 1
Views: 273

### Calculating Kinetic Energy

Would someone be able to walk me through how to solve this problem:

Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1.
A. What is the kinetic energy of the ejected electron?
Sat Jul 06, 2019 9:05 pm
Forum: Properties of Light
Topic: wavelength
Replies: 11
Views: 1005

### Re: wavelength

Yes, the wavelength is the distance between two peaks. But, this is only one definition. The wavelength can also be the distance between two troughs. Or, a wavelength can just be the distance between two sequentially equivalent points. When a wave passes the same starting point, that is what determi...
Sat Jul 06, 2019 9:02 pm
Forum: Photoelectric Effect
Topic: kinetic energy of electron
Replies: 8
Views: 659

### Re: kinetic energy of electron

An electron will have zero kinetic energy (Ek) when there is no excess energy left over from the photoelectric effect. Look at the equation below: E(photon)-E(remove an electron)=E(excess) OR E(photon)-(work function)=Ek When we set Ek equal to zero, the equation becomes: E(photon)=E(remove an elect...
Sat Jul 06, 2019 8:54 pm
Forum: Einstein Equation
Topic: Energy of photon [ENDORSED]
Replies: 12
Views: 1031

### Re: Energy of photon[ENDORSED]

Yes. In order to calculate the energy of a photon you use the equation E=hv.
E=energy of a photon in Joules
h=Planck's constant (6.626*10^-34 J*s)
v=frequency of wave in Hz
Sat Jul 06, 2019 8:50 pm
Forum: Photoelectric Effect
Topic: Photo electric effect
Replies: 7
Views: 574

### Re: Photo electric effect

The photoelectric experiment has to be done under a vacuum otherwise the ejected electrons will mix and interact with molecules in the air which can disrupt and ruin the experiment.
Sat Jul 06, 2019 8:46 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chromium and Copper [ENDORSED]
Replies: 1
Views: 292

### Re: Chromium and Copper[ENDORSED]

Chromium's (Cr) electron configuration is: [Ar] 3d^5 4s^1

Copper's (Cu) electron configuration is: [Ar] 3d^10 4s^1
Sat Jul 06, 2019 8:42 pm
Forum: Balancing Chemical Reactions
Topic: Balancing Equations
Replies: 5
Views: 737

### Re: Balancing Equations

In order to find the net number of moles produced, you have to add up the number of moles on the reactants and products side and then subtract the number of moles on the reactants side from the number of moles on the products side. So, for the first two you would do: A. (16+20)-(4+26)=6 B. (16+18)-(...
Sun Jun 30, 2019 2:33 pm
Forum: Empirical & Molecular Formulas
Topic: Naming Compounds
Replies: 1
Views: 241

### Re: Naming Compounds

I'm pretty sure we don't need to know how to name compounds, especially some of the anions shown on the table. But, I would just know the basics. For example, I would know the main diatomic gases which are oxygen, nitrogen, hydrogen and chlorine gas (and others). All of these gases contain two atoms...
Sun Jun 30, 2019 2:18 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: What does dilution mean in a chemistry problem?
Replies: 8
Views: 404

### Re: What does dilution mean in a chemistry problem?

Dilution is when you are adding more solvent to a solution which contains solute and already some solvent. More often than not, the solvent that is being added is distilled water. A dilution leads to an increase in liters of solution and decreases the molarity of the solution.
Sun Jun 30, 2019 2:13 pm
Forum: Balancing Chemical Reactions
Topic: H5 7th edition
Replies: 4
Views: 343

### Re: H5 7th edition

Yes, the subscript does count toward balancing the chemical equations. For example, if you have MgSO4, the subscript is the 4. In this case, the 4 means that there are 4 oxygen atoms. So whenever you have a subscript that comes after an element, it refers to the number of atoms of that element. Anot...
Sun Jun 30, 2019 2:08 pm
Forum: Balancing Chemical Reactions
Topic: Combustion Equation
Replies: 21
Views: 1301

### Re: Combustion Equation

In a combustion reaction there is always of hydrocarbon molecule and oxygen gas in the reactants. These two reactants combine to form carbon dioxide and water molecules as the products. I heard this is a very important concept to understand, so I'd go over some problems related to it in the homework!
Thu Jun 27, 2019 7:12 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamental Units?
Replies: 2
Views: 301

### Fundamental Units?

In a lot of the homework problems we were asked to calculate the fundamental units of different molecular compounds. What exactly are fundamental units and how do you solve for them? Here is an example problem from Fundamentals E.25: (a) Determine the number of KNO3 formula units in 0.750 mol KNO3. ...
Wed Jun 26, 2019 6:56 pm
Forum: Molarity, Solutions, Dilutions
Topic: Homework Problem G.13 in Fundamentals
Replies: 3
Views: 349

### Homework Problem G.13 in Fundamentals

How would you go about solving homework problem G.13 in Fundamentals Exercises? The question is also shown below: To prepare a fertilizer solution, a florist dilutes 1.0 L of 0.20 m NH4NO3(aq) by adding 3.0 L of water. The florist then adds 100. mL of the diluted solution to each plant. How many mol...