What is Pchem: Definition and 14 Discussions

Physical chemistry is the study of macroscopic, and particulate phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical mechanics, analytical dynamics and chemical equilibrium.
Physical chemistry, in contrast to chemical physics, is predominantly (but not always) a macroscopic or supra-molecular science, as the majority of the principles on which it was founded relate to the bulk rather than the molecular/atomic structure alone (for example, chemical equilibrium and colloids).
Some of the relationships that physical chemistry strives to resolve include the effects of:

Intermolecular forces that act upon the physical properties of materials (plasticity, tensile strength, surface tension in liquids).
Reaction kinetics on the rate of a reaction.
The identity of ions and the electrical conductivity of materials.
Surface science and electrochemistry of cell membranes.
Interaction of one body with another in terms of quantities of heat and work called thermodynamics.
Transfer of heat between a chemical system and its surroundings during change of phase or chemical reaction taking place called thermochemistry
Study of colligative properties of number of species present in solution.
Number of phases, number of components and degree of freedom (or variance) can be correlated with one another with help of phase rule.
Reactions of electrochemical cells.

View More On Wikipedia.org
  1. DrSteve

    Programs Is a 3.4 GPA enough for a PhD in Organic Chemistry?

    Hi all, I know that some you have chemistry backgrounds (mine is in nuclear physics), so wanted to pose a question for a friend who is a chemist and is thus not on this site. He has a degree in biology, with emphasis on synthetic organic chemistry. His overall GPA was ~ 3.2 (3.4 in major). He...
  2. Ariel Jo

    What is the standard free energy change for the decomposition of pyruvic acid?

    Homework Statement Consider the reaction of pyruvic acid (CH3COCOOH) into gaseous acetaldehyde (CH3CHO) and gaseous CO2, which is catalyzed an aqueous solution by the enzyme pyruvate decarboxylase. Assume ideal gas behavior only for the CO2. (a) Calculate ∆298 0 for this reaction. (b) Calculate...
  3. S

    Pchem -- de Brogile relation question phrasing....

    Electrons are accelerated in an electrical potential of: ΔΦ = 105 V and are focused on a biological specimen. Assume that the kinetic energy of an electron is given by eΔΦ where e is the charge of an electron. What is the smallest possible object that can be resolved assuming that the...
  4. H

    Voltage drop question - need check/advice

    1. Homework Statement What do you predict the voltage will be measured from B to D directly? Vtot = 1.0 V peak-peak Two parallel branches, one with two 1.5 kOhm resistors in series, one with a 1.5 kOhm resistor and a 0.1 μF capacitor in series (see attached diagram) Homework Equations V=IR...
  5. C

    [PChem] Maxwell-Boltzmann Molecule Mean Speed

    Hi, I am having trouble with this concept... "A mean speed (c) is calculated by multiplying each speed by the fraction of molecules that have that speed, and then adding all the products together. When the speed varies over a continuous range, the sum is replaced by an integral. To employ...
  6. C

    [PChem] Van de Waals Partial Derivative

    Homework Statement Find (\frac{dV}{dp})_{n,T} for the Van de Waals gas law Homework Equations Van de Waals gas law: (\frac{p+an^2}{V^2})(V-nb)=nRT The Attempt at a Solution I just started doing problems like these so I would like to know if I am doing them right... What I did was I took...
  7. J

    PChem: Calculating pH with Na2HPO4 and NaH2PO4*7H2O

    Homework Statement 8.9985 g of Na2HPO4 and 4.0211 g of NaH2PO4 * 7 H2O are added to 1 L of 0.20 M KCl in water. KCl does not participate in any way but to maintain ionic strength, at 0.20 M. H3PO4 (aq) + H2O → H2PO4- (aq) + H3O+, Ka1 = 7.11 x 10-3 Ka2 = 6.32 x 10-8 Ka3 = 7.1 x 10-13 (a)...
  8. H

    Kinetics of Pchem Ques: Adsorption, Desorption, Rate Consts

    1. question http://farm9.staticflickr.com/8282/7804721900_bd0b895954_b.jpg On a catalyst surface, the formation reaction of CO2 by the oxidation of CO with O2 proceeds in the following mechanism. (1) O2(g) + 2V <---> 2O(ads) (equilibrium constant KO2) (2) CO(g) + V <--> CO(ads)...
  9. B

    What is the recommended background for PChem?

    I want to take PChem, but I'm wondering if I should wait until I have a deeper understanding of quantum mechanics and electricity and magnetism. I've seen QM in a modern physics class and I've taken a sophomore level E&M class. I've got my calculus down pretty well, and I've taken two...
  10. L

    Solve Thermodynamic Problems: Ideal Gas Expansion & Energy Conservation

    i really need help with my homework if people can help lead me to the answer it would be really helpful. so far i was only able to do number 1 1) If 2.00 mol of an ideal gas, initially at 1.53 atm and 280 K, is allowed to expand isothermally under a constant external pressure of 0.920 atm...
  11. B

    2 questions (one ochem and one pchem)

    For organic chemistry, in an experiment, how does the epimerization (of H) of Potassium carbonate work? Does carbonate work as a base and deprotonate a hydrogen and then by refluxing it do you get an epimer? For the pchem part, If the 3.0g of gas occupies 11.2L at 0.0C and 0.25 atm, then...
  12. T

    PChem Question: pV work reversibility/irreversibility

    Hi, Here's an idea I can't quite figure out the answer to. If we were to set up a container of an ideal gas (say He) that had a movable lid such that the lid did not interact with the walls to generate friction or the like. On top of the lid we place a brick which is able to hold the lid...
  13. W

    Can Gas A or B be liquefied and do they have a critical temperature?

    Homework Statement The following equations of state are occasionally used for approximate calculations on gases: (gas A) pVm = RT(1+b/Vm), (gas B) p(Vm -b) = RT. Assuming that there were gases that actually obeyed these equations of state, would it be possible to liquefy either gas A or B...
  14. C

    Which Should I Take First: Analytical Chemistry or Physical Chemistry?

    I will be picking my Spring courses on Monday and I just want to know which class you would recommend me taking first: analytical chem or physical chemistry? does it matter which I take first? I will have to take physical chemistry 2, so should I take physical chemistry first because of that...