## Search found 13 matches

Mon Mar 07, 2016 8:00 pm
Forum: *Carboxylic Acids
Topic: Functional groups vs. Substituents
Replies: 2
Views: 3206

### Re: Functional groups vs. Substituents

Substituent are essentially Hydrocarbon chains that are shorter than and connected to the parent chain. (They are missing one H where the fist Carbon is bound to the parent chain and they therefore are actually called Hydrocarbyls). Hydrocarbons, by definition, consist of Hydrogen and Carbon atoms t...
Mon Feb 29, 2016 8:51 am
Forum: *Alkanes
Topic: Carbo cations
Replies: 1
Views: 296

### Re: Carbo cations

If a double bond in an hydrocarbon (alkene) is acting as a nucleophile, then it attacks an electrophile with its pi electrons. So the double bond will be replaced by a single bond. But rather than each previously double bounded carbon atom getting one electron each (which would leave them neutral li...
Mon Feb 22, 2016 8:53 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units of k
Replies: 3
Views: 520

### Re: Units of k

Yes, we can determine the order of a reaction by looking at the units of the rate constant.
Mon Feb 15, 2016 1:48 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Units of k
Replies: 3
Views: 520

### Re: Units of k

From the order and/or rate law of the reaction. We know for sure that the rate will have the units mol per liter per second written as [mol x L^(-1) x s^(-1)] or [M/s]. So you need to know order of the reaction to write the rate in the form; rate=k x [A]^(order). As we can see the order determines t...
Mon Feb 08, 2016 12:50 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Using ∆Go to Find Eo
Replies: 2
Views: 478

### Re: Using ∆Go to Find Eo

Adding those two reductions would be different than adding a reduction to the reverse of another reduction (so, an oxidation) in a way that cancels electrons and ends up being a redox reaction. The latter works and that's what we do to come with a galvanic cell. But the standard potentials are not a...
Mon Feb 01, 2016 8:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram (14.11 b)
Replies: 2
Views: 312

### Re: Cell Diagram (14.11 b)

When building a battery, the reaction with a higher standard potential always remains as the reduction, so becomes the cathode. The one with a smaller standard potential is reversed, so it is the anode as the reversed reaction is now an oxidation. This way you get a positive potential for the cell, ...
Mon Jan 25, 2016 8:10 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Quiz prep 2015 number 3
Replies: 2
Views: 500

### Re: Quiz prep 2015 number 3

Mon Jan 25, 2016 8:02 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Question #11 on Practice Quiz 1 2015
Replies: 3
Views: 444

### Re: Question #11 on Practice Quiz 1 2015

Since the question asks for the moles of water that can be heated with the q of that reaction, you should assume there is no heat lost out of the system. You're given the enthalpy change for 1 mole of PbO->Pb reaction so calculate how many moles you actually have using n=m/M and multiply with the gi...
Mon Jan 18, 2016 9:37 pm
Forum: Calculating Work of Expansion
Topic: Internal energy and work
Replies: 2
Views: 470

### Re: Internal energy and work

The examples only had expansion work and some specifically mentioned that there was no non-expansion work. Volume change means expansion work being done by or to the system. Any statement regarding constant volume, therefore, would mean no expansion work.
Wed Jan 13, 2016 6:57 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 1
Views: 237

### Re: Hess's Law

The data given to you consists of combustion enthalpies. That's why you will need to write the balanced combustion reactions as well as the hydrogenation reaction you are looking for. Once you write the combustions, you have three reactions with known enthalpies as you need to use for Hess's Law. Si...
Sat Jan 09, 2016 5:25 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework 8.25
Replies: 5
Views: 2949

### Re: Homework 8.25

What you are doing is correct. The proportion of temperature change to the released energy (-3.50kJ/7.32 C) gives you the heat capacity of the calorimeter, because heat capacity is " the amount of energy required to raise the temperature of an object one degree." And it is a constant for t...
Sat Jan 09, 2016 12:45 am
Forum: Phase Changes & Related Calculations
Topic: HW 8.61 Enthalpy for synthesis of HBr
Replies: 1
Views: 304

### Re: HW 8.61 Enthalpy for synthesis of HBr

The last reaction with the product NH4Br has the standard formation enthalpy of that compound. It is formed by the elements in their standard state. You can then reverse the first reaction with the given enthalpy (changing the sign of the enthalpy in the process) in order to obtain HBr as product. -...
Tue Nov 24, 2015 8:20 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: how to calculate Kc and K (video)
Replies: 1
Views: 455

### how to calculate Kc and K (video)

This is our video that shows how to calculate Kc and K. Also, it shows how to make an ICE box and how to calculate for equilibrium concentrations.

Produced by Santhosi Samudrala(4C) and Tara Kubilay(1H)