## Search found 12 matches

Wed Mar 07, 2018 3:09 am
Forum: First Order Reactions
Topic: 15.23C
Replies: 6
Views: 382

### Re: 15.23C

Not necessarily. A second order reaction would have two different reactants. This reaction has two of the same reactant.
Wed Mar 07, 2018 3:06 am
Forum: General Rate Laws
Topic: 15.3
Replies: 4
Views: 218

### Re: 15.3

The reaction that breaks apart the NO2 progress in the forward direction. Thus, the rate of the reaction is negative. On the flip side, if the reaction rate was negative, then reactants would be forming (i.e. NO2).
Wed Mar 07, 2018 3:03 am
Forum: *Complex Reaction Coordinate Diagrams
Topic: Unique Rate. [ENDORSED]
Replies: 4
Views: 1216

### Re: Unique Rate.[ENDORSED]

Yeah, that's correct. To find the specific rate of consumption/formation of a reagant, you multiply the unique rate of the equation to the reagant's coefficient.
Sat Feb 24, 2018 5:14 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.23 (c)
Replies: 3
Views: 163

### Re: 14.23 (c)

In this instance, I feel it is important to keep the H+ on the side with the Cr2O7^2- because the H+ is used to balance out the H20 that is used to balance out the O in the half reaction involving Cr207^2-.
Sat Feb 24, 2018 4:55 pm
Forum: Balancing Redox Reactions
Topic: Writing and Balancing Half Reactions
Replies: 6
Views: 352

### Re: Writing and Balancing Half Reactions

1. Identify which species is being oxidized and which is being reduced (ignore H and O, and use changes in oxidation numbers) 2. Write the half-reactions for the oxidizing and reducing reagents identified in step 1. 3. For each one, balance the oxygen by adding H2O to the other side for each O you n...
Sat Feb 24, 2018 4:51 pm
Forum: Balancing Redox Reactions
Topic: 14.5 a)
Replies: 5
Views: 267

### Re: 14.5 a)

You add OH when balancing the half reaction because it is in a basic solution. If it were in an acidic solution you would add H+.
Sun Jan 21, 2018 10:45 pm
Forum: Calculating Work of Expansion
Topic: What do these variables mean?
Replies: 4
Views: 220

### Re: What do these variables mean?

You are correct. F is force, A is area, D is distance. Interestingly Force can be defined as pressure over an area (F = P * A) and when that is put into the work equation (w = F * D), it becomes F = P * A * D. Then, A * D can simplify to ΔV because it represents the difference in volume before and a...
Sun Jan 21, 2018 10:21 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: calculating specific heat
Replies: 5
Views: 296

### Re: calculating specific heat

For specific heat capacity, volume is not necessary unless you need it to find mass. For example, you would need volume to find mass if you are given density and volume or molarity, volume, and molar mass.
Sun Jan 21, 2018 10:13 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: work definition
Replies: 5
Views: 282

### Re: work definition

Work is the measurement of energy required for any action, measured in Joules. Its definition is often represented by w = F * d which means work equals Force times distance; this reflects that work is also defined as force over any distance. Force, however, can come in many different forms. For exam...
Sun Jan 14, 2018 12:14 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy of Formation from Most Stable Form
Replies: 3
Views: 428

### Re: Standard Enthalpy of Formation from Most Stable Form

The standard enthalpy of formation for an element in its most stable form is zero because, being already in its most stable form, it requires zero enthalpy of formation to get to its most stable form. There is no need for a change in heat to reach a form that it already exists in. Usually, we use th...
Sun Jan 14, 2018 12:07 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy of physical change?
Replies: 3
Views: 314

### Re: Enthalpy of physical change?

I think it is good to first understand that when a substance undergoes a phase transition (physical change), its temperature does not change while its phase changes even though energy is being added into the system. The enthalpy was calculated by measuring the initial and final values and subtractin...
Sat Jan 13, 2018 11:54 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Bomb Calorimetry
Replies: 4
Views: 770

### Re: Bomb Calorimetry

A bomb calorimeter's outstanding feature is its ability to measure heat under constant volume, in contrast to the coffee cup calorimeter which measures heat under constant pressure (enthalpy). The bomb calorimeter accomplishes this distinction, hopefully, by containing the experiment within a box (u...