Search found 10 matches
- Thu Mar 16, 2017 2:26 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3591123
Re: Post All Chemistry Jokes Here
Chemist on the phone
- Thu Mar 09, 2017 11:26 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3591123
Re: Post All Chemistry Jokes Here
The Periodic Table as seen by an Organic Chemist
- Wed Mar 01, 2017 1:24 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3591123
Re: Post All Chemistry Jokes Here
Why did the bear dissolve in water?
He was a POLAR bear!
He was a POLAR bear!
- Mon Feb 20, 2017 11:24 am
- Forum: General Rate Laws
- Topic: Ch 15 Exercise 3a
- Replies: 1
- Views: 512
Ch 15 Exercise 3a
In 20.s, the concentration of nitrogen dioxide, NO2, decreases from 450 mmol/L to 320 mmol/L in the reaction 2NO2\rightarrow 2NO+O2 (a) Determine the rate of reaction of NO2 Why is the correct answer 6.5 mmol/L x sec and not -6.5 mmol/L x sec? Shouldn't the rate of reaction be negative because NO2 i...
- Tue Feb 14, 2017 9:58 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Ch 8 Exercise 41
- Replies: 1
- Views: 406
Ch 8 Exercise 41
A 50.0g ice cube at 0.0 degrees Celsius is added to a glass containing 400.0g of water at 45.0 degrees Celsius. What is the final temperature of the system? Assume that no heat has been lost to the surroundings. Why do we use this equation to solve the problem? And why are the equations set equal to...
- Wed Feb 08, 2017 9:56 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Ch 14 Exercise 43
- Replies: 1
- Views: 616
Ch 14 Exercise 43
A tin electrode in 0.015M Sn(NO3)2 (aq) is connected to a hydrogen electrode in which the pressure of H2 is 1.0 bar. If the cell potential is 0.061 V at 25 degrees Celsius, what is the pH of the electrolyte at the hydrogen electrode? Which equation are we supposed to use to solve this problem? Thanks!
- Wed Feb 01, 2017 11:28 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Equation Explanation
- Replies: 1
- Views: 413
Equation Explanation
Does the equation delta S=q/T only apply to ideal gases? Or does it apply to any isothermal, reversible process?
Also, are there any differences between the equations delta S=q/T and delta S=q(rev)/T?
Thanks!
Also, are there any differences between the equations delta S=q/T and delta S=q(rev)/T?
Thanks!
- Wed Jan 25, 2017 4:54 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Ch 8 Exercise 107
- Replies: 2
- Views: 568
Ch 8 Exercise 107
A person of average mass burns about 30 KJ/minute playing tennis. Find the time you would have to spend playing tennis to burn up the energy in a 2.0 oz serving of cheese, which has a specific enthalpy of combustion of 17.0 KJ/gram. What is the difference between specific enthalpy and specific entha...
- Thu Jan 19, 2017 4:10 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Ch 8 Exercise 77
- Replies: 3
- Views: 930
Ch 8 Exercise 77
8.77) Benzene is more stable and less reactive than would be predicted from its Kekule structures. Use the mean bond enthalpies in Table 8.7 to calculate the lowering in molar energy when resonance is allowed between the Kekule structures of benzene. What is a Kekule structure and what effect does r...
- Wed Jan 11, 2017 6:08 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Ch.8 Exercise 31
- Replies: 2
- Views: 512
Ch.8 Exercise 31
Calculate the heat released by 5.025g of Kr(g) at 0.400 atm as it cools from 97.6 degrees Celsius to 25.0 degrees Celsius at (a) constant pressure and (b) constant volume. Assume that krypton behaves as an ideal gas. What are the equations used to solve this problem and why do we need to use two dif...