Search found 16 matches

by jennywu
Sun Dec 10, 2017 10:11 pm
Forum: Empirical & Molecular Formulas
Topic: Finals Question about Empirical Formula [ENDORSED]
Replies: 2
Views: 382

Re: Finals Question about Empirical Formula [ENDORSED]

Yes that's what I did too. I found the grams of C and H and then took away the sum of grams of C and H to from the given mass of the unknown compound to find the grams of O.
by jennywu
Sun Dec 10, 2017 9:59 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: pH [ENDORSED]
Replies: 3
Views: 620

Re: pH [ENDORSED]

With a strong acid base reaction, calculate the number of moles of H+ in the solution and then the number of moles of OH- added.
H+ + OH- --> H2O
Then take away number moles of OH- from initial H+ concentration to result in final concentration of H+. Then calculate the pH.
by jennywu
Sun Dec 03, 2017 11:47 pm
Forum: Identifying Acidic & Basic Salts
Topic: 12.51
Replies: 1
Views: 247

Re: 12.51

The strength of an acid, depends on electronegativity: The higher the electronegativity of a conjugate base in the same period, the more acidic. In other words, the more electronegative A- is, more acidic (where HA → H+ + A−).
by jennywu
Sun Dec 03, 2017 11:20 pm
Forum: Bronsted Acids & Bases
Topic: Homework 12.49
Replies: 1
Views: 115

Re: Homework 12.49

The hypobromite ion is the stronger base, BrO- is the conjugate base of HBrO. HBrO is a weak acid therefore, BrO- must be a relatively strong base.
by jennywu
Sun Nov 26, 2017 8:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pairs
Replies: 1
Views: 130

Re: Lone Pairs

VSEPR theory predicts the structure where lone pairs occupy positions that allow them to experience less repulsion. Lone pair-lone pair repulsions are considered stronger than lone pair-bonding pair and bonding pair-bonding pair repulsions. The bonding pair shared in a bond lies further from the ato...
by jennywu
Sun Nov 26, 2017 8:18 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: CO3 2-
Replies: 1
Views: 162

Re: CO3 2-

One of the Lewis resonance structures of CO3 2- has 1 C=O double bond and 2 C-O single bonds. Each of the O's in the single bonds is able to bind to a metal centre, making CO3 2- a bidentate ligand. The other resonance structure has 2 C=O double bonds and 1 C-O bond. The O- in the C-O bond is able t...
by jennywu
Sun Nov 19, 2017 4:27 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Naming Coordination Compounds
Replies: 4
Views: 225

Re: Naming Coordination Compounds

for the naming of the compound, it follows the IUPAC naming convention where the cyanide turns into the prefix cyano
by jennywu
Sun Nov 19, 2017 4:17 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Multiple Oxidation States
Replies: 1
Views: 108

Re: Multiple Oxidation States

Transition metals have electrons in the d orbital. As the number of unpaired valence electrons increases, the d-orbital increases, the highest oxidation state increases. This is because unpaired valence electrons are unstable and eager to bond with other chemical species. Iron, has 3d orbital and 4s...
by jennywu
Sun Nov 05, 2017 10:07 pm
Forum: Resonance Structures
Topic: Delocalized electrons
Replies: 4
Views: 238

Re: Delocalized electrons

Delocalized electrons are spread across more than one atom or shared. Think of it as an electron probability cloud spread over the entire molecule or between two atoms at any given moment the moving electron could be anywhere in that cloud. In one instant it could be forming bonds with one atom and ...
by jennywu
Sun Nov 05, 2017 9:55 pm
Forum: Properties of Electrons
Topic: Energy Levels and Frequencies
Replies: 3
Views: 340

Re: Energy Levels and Frequencies

The Lyman series is a hydrogen spectral series of transitions and results from ultraviolet emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n = 1, the lowest energy level of the electron. As the distances between energy levels get smaller as the energy level increases, electrons...
by jennywu
Sun Oct 29, 2017 8:55 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: 4s and 3d orbitals
Replies: 5
Views: 426

Re: 4s and 3d orbitals

According to the Aufbau principle, the 4s sublevel is filled before the 3d sublevel because the 4s is lower in energy. However, when the 3d orbital starts to become filled, the energies of 4s and 3d fluctuate and 4s ends up higher than 3d energy level. so electrons are lost from 4s first.
by jennywu
Sun Oct 29, 2017 8:51 pm
Forum: Properties of Electrons
Topic: Energy level question [ENDORSED]
Replies: 2
Views: 247

Re: Energy level question [ENDORSED]

Because n=1 is the smallest orbital and orbital size increases with increased energy. The orbital number represents the amount of energy released when the electron moves from being a "free" electron to the orbital it occupies. The more energy is released the lower the energy ends up being ...
by jennywu
Sun Oct 15, 2017 11:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Ground state vs excited state
Replies: 3
Views: 235

Re: Ground state vs excited state

Electrons in the ground state will fill up orbitals starting with the lowest energy orbital 1s, 2s, 2p, 3s, 3p, 4s, 3d etc. Check the electron configuration and see if there have been any electrons excited to a higher energy level/ if there are any electron orbitals in lower energy states that have ...
by jennywu
Sat Oct 14, 2017 3:04 pm
Forum: Empirical & Molecular Formulas
Topic: What order do the atoms go in [ENDORSED]
Replies: 1
Views: 172

Re: What order do the atoms go in [ENDORSED]

In Chemistry the Hill System is followed when writing empirical/ molecular formulas where Carbon atoms are written first then Hydrogen and then all other atoms alphabetically
by jennywu
Fri Oct 06, 2017 1:42 am
Forum: Limiting Reactant Calculations
Topic: Exercise M.11 [ENDORSED]
Replies: 3
Views: 301

Re: Exercise M.11 [ENDORSED]

Hi there, For this question i first calculated the moles of O2 in the first reaction using the value given of 5.77g. Which gave me the answer of 0.1803. Nxt, I calculated the moles of P4 using 5.77 value given. Giving me an answer of 0.04657. Because P4: O2 is a 1:3 ratio. Then for every 0.04657 mol...
by jennywu
Fri Oct 06, 2017 1:29 am
Forum: Empirical & Molecular Formulas
Topic: Problem L.35
Replies: 2
Views: 231

Re: Problem L.35

Firstly, balance the equations Fe + Br --> FeBr2 3FeBr2 + Br2 --> FeBr8 Fe3Br8 + 4Na2CO3 --> 8NaBr + 4CO2 + Fe3O3 Then convert tonnes into kgs. m= 2.5t= 2500kg You can merge all the above equations into one big equation. Whereby all the reactants of all three reactions go on the left hand side and a...

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