Search found 21 matches
- Sat Mar 12, 2016 10:40 pm
- Forum: *Cycloalkenes
- Topic: Ortho, meta, para
- Replies: 1
- Views: 380
Ortho, meta, para
Will we be tested on substituent position in terms of ortho, meta and para positions in cycloalkenes, specifially benzene?
- Sat Mar 12, 2016 5:05 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Sig Fig question
- Replies: 1
- Views: 339
Sig Fig question
If the lowest number of sig figs in the question is 1, but a value (like standard electrode potential) on the sheet with values has 2 sig figs, should the answer contain 1 sig fig or two?
- Sat Mar 12, 2016 3:07 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Winter 2008 Final
- Replies: 1
- Views: 311
Re: Winter 2008 Final
When A is kept constant and B is doubled (increased from 0.1 to 0.2), the rate is also doubled. Hence, the factor of increase of B is equal to the factor of increase of the rate. In other words, in both trial 1 and trial 3, Initial rate/[B]=50. When a reaction is first order, when a reactant is incr...
- Mon Feb 29, 2016 3:46 am
- Forum: *Aldehydes
- Topic: aldehyde must end
- Replies: 2
- Views: 849
Re: aldehyde must end
This is because an Aldehyde functional group looks like this: CHO, where carbon is double bonded to oxygen, and single bonded to hydrogen. This carbon is also connected to another carbon atom, like this: C-C-C-CHO. So it's got all 4 valences filled (1 by carbon, 1 by hydrogen, 2 by oxygen), so it ha...
- Wed Feb 17, 2016 9:37 pm
- Forum: Second Order Reactions
- Topic: Units for Second Order
- Replies: 2
- Views: 947
Re: Units for Second Order
Units for k work like this: M^{(1-n)}s^{-1} or (L\cdot mole^{-1})^{(1-n)}s^{-1} Where n is the order of the reaction. In your question, M^{-4} implies that (1-n)=-4. Hence n=5, or the reaction is fifth order. Similarly for (1-n)=-3, the reaction is 4th order. Hope this helps :)
- Mon Feb 08, 2016 6:03 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Midterm 2011 Q4
- Replies: 1
- Views: 288
Re: Midterm 2011 Q4
The question states: "the partial pressure for each of the reactants is equal to half that of the product."
Hence they've assumed that P(PCl3) and P(Cl2) are equal to x, and P(PCl5) is equal to 2x, since it is twice the value of that of the reactants.
Hence they've assumed that P(PCl3) and P(Cl2) are equal to x, and P(PCl5) is equal to 2x, since it is twice the value of that of the reactants.
- Fri Feb 05, 2016 2:06 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Half equations
- Replies: 1
- Views: 334
Re: Half equations
H2O -> O2 + H+ + e- (oxidation)
H2O + e- -> H2 + OH- (reduction)
H2O + e- -> H2 + OH- (reduction)
- Fri Jan 29, 2016 5:55 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation state
- Replies: 1
- Views: 358
Re: Oxidation state
The values of the oxidation state and oxidation number of an element are commonly equal, but there is a slight difference between the terms. Oxidation state refers to the degree of oxidation of an element in a molecule, where the sum of all oxidation states of elements in that molecule or ion gives ...
- Thu Jan 21, 2016 8:31 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Relating q, w, U, and H
- Replies: 1
- Views: 416
Re: Relating q, w, U, and H
q=-w for an isothermal process. This is because \Delta U=-3/2k\Delta T For an isothermal process, ∆T=0, hence ∆U=0 We also know that ∆U= q+w Since ∆U=0, q+w=0 Hence q=-w for an isothermal process. We know ∆U= q+w For a system where the volume is constant, the gas is not doing any work of expansion, ...
- Fri Jan 15, 2016 12:31 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Examples of different thermodynamic systems
- Replies: 1
- Views: 402
Re: Examples of different thermodynamic systems
Open system: A glass of water
Closed system: A sealed soda bottle
Isolated system: A well made thermos
Note: No system (barring the universe itself - even this is debated) is truly isolated. The best thermos in the world will still leak some energy.
Closed system: A sealed soda bottle
Isolated system: A well made thermos
Note: No system (barring the universe itself - even this is debated) is truly isolated. The best thermos in the world will still leak some energy.
- Sun Jan 10, 2016 2:09 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Specific Heat Under Const. Press. vs. Const. Vol.
- Replies: 2
- Views: 477
Re: Specific Heat Under Const. Press. vs. Const. Vol.
Yes. Since gases have a tendency to expand (increase in volume) when heated, if you don't allow them to expand (by keeping the volume constant), the pressure will increase. For example, this is why balloons explode when exposed to a flame, because the volume of the balloon is kept constant, but the ...
- Thu Dec 03, 2015 4:44 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shape when dealing with polydentates
- Replies: 2
- Views: 487
Re: Shape when dealing with polydentates
Coordination number and shape would not change between mono dentate and bidentate ligands (of the the same coordination number), but the number of ligands in the case of mono dentate ligands will be higher (4) than bidentate ligands (2)
- Thu Dec 03, 2015 3:45 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Shapes
- Replies: 2
- Views: 556
Re: Shapes
Another way to explain this is through hybridization. There are concepts known as Crystal Field Theory and Valence Bond Theory which we have not covered, but the basic explanation is this: Since the coordination number on the central metal atom is 6, this means it is surrounded by 6 coordinate bonds...
- Thu Dec 03, 2015 3:22 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Naming shape of compounds
- Replies: 2
- Views: 548
Re: Naming shape of compounds
The only commonly encountered coordination numbers for complex compounds are 4 and 6.
When coordination number is 4, the shape is tetrahedral
When coordination number is 6, the shape is octahedral.
When coordination number is 4, the shape is tetrahedral
When coordination number is 6, the shape is octahedral.
- Thu Dec 03, 2015 3:20 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: 17.37 Determine coordination number
- Replies: 4
- Views: 1729
Re: 17.37 Determine coordination number
Here are the answers to those questions, hopefully it will help you understand the concept.
a) 4
b) 2
c) 6
d) 6
a) 4
b) 2
c) 6
d) 6
- Thu Dec 03, 2015 3:08 pm
- Forum: Lewis Structures
- Topic: Determining which element to give a formal charge
- Replies: 3
- Views: 621
Re: Determining which element to give a formal charge
Chlorine can never form a double covalent bond with any element, as it would then have 10 electrons in its orbits, and it cannot hold an expanded octet. Chlorine always forms a single bond. Now for the oxygens, one would be connected to the Sulfur with a double bond (FC = 0), and the other with a si...
- Wed Dec 02, 2015 2:40 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: When to move electrons from the s orbital to d orbital
- Replies: 1
- Views: 2111
Re: When to move electrons from the s orbital to d orbital
The electron config of Nickel would not be [Ar]3d^10 It's [Ar]3d^84s^2 Only one electron can be moved from the s orbital to the d orbital when fulfilling the half-filled subtle rule. This is why the electron config of Copper is [Ar]3d^{10}4s^1 and not [Ar]3d^94s^2 Similarly, the configuration of Van...
- Thu Nov 19, 2015 9:24 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: T-Shaped Molecule and its Dipole Moments
- Replies: 3
- Views: 2058
Re: T-Shaped Molecule and its Dipole Moments
T shaped molecules are always polar.
In both cases (octahedral and trigonal bipyramidal), the bond angles will be slightly less than 90 and 180 due to lone pair-bond pair repulsion.
In both cases (octahedral and trigonal bipyramidal), the bond angles will be slightly less than 90 and 180 due to lone pair-bond pair repulsion.
Re: NAMING
Ferrate is used when the complex is an anion, iron is used when the complex is a cation.
- Tue Oct 27, 2015 9:00 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW 3.25
- Replies: 1
- Views: 304
Re: HW 3.25
Hydrogen reacts differently with metals, metalloids and non-metals. With metalloids and non-metals, Hydrogen is usually more electropositive (likes to donate electrons more) than the other element, leading to an oxidation state of +1, as is reflected in H_{2}Te However, with metals, Hydrogen is usua...
- Tue Oct 20, 2015 5:18 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Wedges and Dashes
- Replies: 1
- Views: 367
Re: Wedges and Dashes
A dark wedge indicates that that atom is closer to you (the observer) in terms of 3D structure. A dashed wedge is the opposite - it is further away from the observer than the central atom. Their placement is important as it indicates the 3D orientation of a molecule, without which we only have a rou...