Search found 15 matches
- Sat Mar 18, 2017 2:55 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3589714
- Wed Mar 08, 2017 3:30 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3589714
- Sun Feb 19, 2017 7:42 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3589714
- Sun Feb 12, 2017 9:24 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3589714
- Sun Jan 29, 2017 8:51 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Enthalpy
- Replies: 1
- Views: 1696
Re: Enthalpy
Split the equation 2CH4 + 4O2 ---> 2CO2 + 4H2O Hc for 1 mole of CH4 is 890, so for 2 moles its 1780, add a negative sign since its exothermic 2CO + O2 ----> 2CO2 (Reverse reaction is 2CO2 ----> 2CO + O2) For the reverse reaction, Hc is positive and for 2 moles value is 586 Total value = -1780+586 = ...
- Sun Jan 22, 2017 3:54 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: How to know which method to use? [ENDORSED]
- Replies: 1
- Views: 471
Re: How to know which method to use? [ENDORSED]
We can use any method, but generally the question can be solved by one method only (as it might be at a constant pressure or volume)
- Mon Jan 16, 2017 12:52 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: When can we assume that temperature is 298K?
- Replies: 1
- Views: 496
Re: When can we assume that temperature is 298K?
You should use the temperature given, if the question doesnt mention anything then use STP. (Standard Temperature and Pressure)
- Fri Dec 02, 2016 10:14 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3589714
Re: Post All Chemistry Jokes Here
Are you made of copper and tellurium? Because you're so CuTe
My girlfriend dumped me the next day
My girlfriend dumped me the next day
- Wed Nov 23, 2016 3:35 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE TABLE
- Replies: 1
- Views: 551
Re: ICE TABLE
First balance the given equation. This involves three steps, initial, change and final concentration at equilibrium. Initial concentration is given in the question, if there is no value it is taken as 0. Change is given in terms of x, and the reaction is taken to be in the forward direction, with a ...
- Mon Nov 14, 2016 1:55 pm
- Forum: Naming
- Topic: Quiz 3 Prep
- Replies: 1
- Views: 556
Re: Quiz 3 Prep
While naming compunds you don't look at the starting alphabet of the molecule, but the starting letter of the name of compound. Since NH3 is name as ammine and H20 is named as aqua, arranging it alphabetically, NH3 would come before H20.
- Mon Oct 31, 2016 5:46 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations Exceptions?
- Replies: 3
- Views: 1574
Re: Electron Configurations Exceptions?
You always try to have half filled or fully filled configurations so you can always shift electrons between 4s and 3d to do that
- Fri Oct 21, 2016 7:47 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Relative size of cations and anions
- Replies: 2
- Views: 1026
Relative size of cations and anions
Why are cations smaller than anions?
- Fri Oct 14, 2016 12:43 am
- Forum: Trends in The Periodic Table
- Topic: Atomic Size in a Group
- Replies: 1
- Views: 477
Atomic Size in a Group
Why is Gallium smaller than Aluminum?
- Thu Oct 06, 2016 4:58 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Nodes and Nodal Planes [ENDORSED]
- Replies: 3
- Views: 1029
Nodes and Nodal Planes [ENDORSED]
How many nodes does a 3s orbital have and why?
- Fri Sep 30, 2016 5:07 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Negative Sign for Energy
- Replies: 2
- Views: 591
Negative Sign for Energy
Bohr's postulates state that energy of the emitted photon is equal to Einital - Efinal. This way the energy is positive, but in an example in the course reader the energy had a negative sign before it?