CHEMISTRY COMMUNITY

Johnson Thai 1L

The reaction 2 SO2(g) + O2(g) --> 2 SO3(g) occurs at 25 degrees Celsius and 1 atm in a constant pressure cylinder. Initially, 0.030 mol SO2 and 0.030 mol O2 are present in the cylinder. Part C asks "Assuming that the reaction goes to completion and that the temperature and pressure of the react...

Johnson Thai 1L

I think it depends on the number of substituents. When there are just two substituents, it would make sense to assign the smaller number to the substituent that would be named first alphabetically, and then the second substituent would get the next number. However, when you have three or more substi...

Johnson Thai 1L

The question asks: "The activation energy in organic reaction is known to be 125 kJ/mol. Will this reaction occur at room temperature?" How do I calculate this? I assumed we would use the Arrhenius equation and solve for k, and if k is less than 1, then the reaction wouldn't occur under ro...

Johnson Thai 1L

I believe it is just "significantly large" enough so that the concentrations of B and C remain constant when A is being used up. This way, as stated in the Course Reader, the reaction rate depends on just concentration of A.

Johnson Thai 1L

I understand it is Cv because it is under constant volume due to the fact that the expansion occurs isothermally. However, in Ron's case, the temperature of the balloon actually changes. I'm confused because wouldn't this mean the expansion doesn't occur isothermally?

Johnson Thai 1L

Cu is being oxidized because it is losing two electrons, while Fe^3 is being reduced because it is gaining an electron.

Johnson Thai 1L

Why are Helium, Curium, and Barium considered medical elements?
Because if you can't HEALium or CUREium, you got to BURYem.

Johnson Thai 1L

Why does positive Delta S favor forward processes and why does negative Delta S not? Does "forward" refer to a reaction where a substance goes from a lower energy state to a higher one? Clarification please, thanks.

Johnson Thai 1L

In Chem14A, Ka and Kb dealt with acid and base equilibrium; however, I don't understand how this relates to entropy and how we're supposed to derive this value for calculations? Also, I don't fully understand the concept of entropy. I understand that it is randomness within a system, but in lecture ...

Johnson Thai 1L

In this question, we must find the reaction enthalpy by subtracting the standard enthalpy of formation of all products with the reactants'. However, every time I do this, I get 312 kJ per mole, while the solutions manual says the correct answer is -312 kJ per mole. My math was -1560 - (-1300 + 2 * -...

Johnson Thai 1L

Alright, so for a weak acid, the pH starts low so the stoichiometric point must be above pH 7, and for a weak base, the pH starts high so the stoichiometric point must be below pH 7. However, how would we calculate the EXACT stoichiometric point? For strong acids/bases it's easier because we can jus...

Johnson Thai 1L

When calculating equilibrium constants, we are supposed to disregard what is in the solid or liquid state. However, why don't we disregard the aqueous solution? I thought that an aqueous solution and a liquid were the same thing. Could someone clarify? Thanks.

Johnson Thai 1L

In problem 17.29 in the textbook, the compound [Co(CN)5(OH)2]2- is named aquapentacyanocobaltate(III). However, the Course Reader says H2O is named aqua, and (OH)2 isn't the equivalent of H2O. Could someone clarify this for me? Thanks!

(I thought it would be named pentacyanodihydroxocobaltate(III)).

Johnson Thai 1L

For MO energy diagrams, knowing the atoms' nuclear charge is important. However, I don't really know how to find it. Is nuclear charge the same as the number of valence electrons an atom has? If not, what is it? Thank you! Clarification much needed!

Johnson Thai 1L

The Course Reader states, "But cations are smaller than their parent atoms and anions are larger." However, shouldn't cations be larger than their parent atoms because losing an electron would mean decreasing nuclear charge and thus electrons would be further from the nucleus? Also, should...

Johnson Thai 1L

How exactly do you calculate the angles of each bond? Also, how do these angles affect the molecule? Are we supposed to memorize the angles that correspond to a certain shape, or is there some way to calculate it? Thank you!

Johnson Thai 1L

Why does it become harder to remove an electron when an atom has a net positive charge? I understand the ionization energy becomes higher after the first electron is removed, but why?

Johnson Thai 1L

I need some clarification. Throughout the Course Reader, electrons are described as having "wavelike properties." Why so? There is also an example described where "If you are driving a 1.5E3 kg car at 27.0 m.s-1, what is the De Brogile wavelength of your car? Does your car have any me...

Johnson Thai 1L

I am having trouble understanding the model depicted in the course reader. I understand that it has to do with electrons, but what exactly is happening? Why are the arrows pointing downwards and why are they of different lengths and at different levels? What is "hR"? Help would be apprecia...

CHEMISTRY COMMUNITY

Search found 19 matches

#8.101.c

Re: Multiple possible names

Help on HW 4.30 and the Arrhenius Equation

Re: When B and C is significantly larger than A

Re: midterm 2015 #4&5 B

Re: Reduction and Oxidation [ENDORSED]

Re: Post All Chemistry Jokes Here

Delta S and what it favors?

What is Kb in Entropy? Entropy Clarification? [ENDORSED]

Help on HW 8.57

Finding Stoichiometric Point for Weak Acids/Bases? [ENDORSED]

Difference between aq and l?

Is (OH)2 aqua? [ENDORSED]

How to determine Nuclear Charge? [ENDORSED]

Size of Cations/Anions compared to Parent Atoms

Bond Angles?

Removing 2nd Electron

Wavelike Properties? [ENDORSED]

Energy Level Model [ENDORSED]