Search found 21 matches

by Nitin Joseph
Sat Mar 12, 2016 10:40 pm
Forum: *Cycloalkenes
Topic: Ortho, meta, para
Replies: 1
Views: 321

Ortho, meta, para

Will we be tested on substituent position in terms of ortho, meta and para positions in cycloalkenes, specifially benzene?
by Nitin Joseph
Sat Mar 12, 2016 5:05 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Sig Fig question
Replies: 1
Views: 295

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?
by Nitin Joseph
Sat Mar 12, 2016 3:07 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Winter 2008 Final
Replies: 1
Views: 253

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...
by Nitin Joseph
Mon Feb 29, 2016 3:46 am
Forum: *Aldehydes
Topic: aldehyde must end
Replies: 2
Views: 653

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...
by Nitin Joseph
Wed Feb 17, 2016 9:37 pm
Forum: Second Order Reactions
Topic: Units for Second Order
Replies: 2
Views: 723

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 :)
by Nitin Joseph
Mon Feb 08, 2016 6:03 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Midterm 2011 Q4
Replies: 1
Views: 245

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.
by Nitin Joseph
Fri Feb 05, 2016 2:06 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Half equations
Replies: 1
Views: 284

Re: Half equations

H2O -> O2 + H+ + e- (oxidation)

H2O + e- -> H2 + OH- (reduction)
by Nitin Joseph
Fri Jan 29, 2016 5:55 pm
Forum: Balancing Redox Reactions
Topic: Oxidation state
Replies: 1
Views: 279

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 ...
by Nitin Joseph
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: 347

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, ...
by Nitin Joseph
Fri Jan 15, 2016 12:31 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Examples of different thermodynamic systems
Replies: 1
Views: 345

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.
by Nitin Joseph
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: 400

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 ...
by Nitin Joseph
Thu Dec 03, 2015 4:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shape when dealing with polydentates
Replies: 2
Views: 421

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)
by Nitin Joseph
Thu Dec 03, 2015 3:45 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shapes
Replies: 2
Views: 433

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...
by Nitin Joseph
Thu Dec 03, 2015 3:22 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Naming shape of compounds
Replies: 2
Views: 494

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.
by Nitin Joseph
Thu Dec 03, 2015 3:20 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: 17.37 Determine coordination number
Replies: 4
Views: 819

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
by Nitin Joseph
Thu Dec 03, 2015 3:08 pm
Forum: Lewis Structures
Topic: Determining which element to give a formal charge
Replies: 3
Views: 484

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...
by Nitin Joseph
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: 1373

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...
by Nitin Joseph
Thu Nov 19, 2015 9:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-Shaped Molecule and its Dipole Moments
Replies: 3
Views: 1149

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.
by Nitin Joseph
Sat Nov 14, 2015 8:35 am
Forum: Naming
Topic: NAMING
Replies: 2
Views: 391

Re: NAMING

Ferrate is used when the complex is an anion, iron is used when the complex is a cation.
by Nitin Joseph
Tue Oct 27, 2015 9:00 pm
Forum: Ionic & Covalent Bonds
Topic: HW 3.25
Replies: 1
Views: 264

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...
by Nitin Joseph
Tue Oct 20, 2015 5:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Wedges and Dashes
Replies: 1
Views: 281

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...

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