CHEMISTRY COMMUNITY

Miya Eberlein 1J

Why does NO have greater residual entropy than BF3?

Miya Eberlein 1J

In question 1C it says that ethane has a higher heat capacity than ethane. Why would this be true, wouldn't it be harder to heat up the triple bonds than the double bonds?

Miya Eberlein 1J

Hi, for #31 we're supposed give the overall rate law for the reaction. Why is the overall rate law for this reaction just the first step of the reaction? is there some significance to that? Also, why is the rate constant larger for the second step, if it requires less activation energy? I'm having t...

Miya Eberlein 1J

Hi! for question 25 in chapter 4 we're supposed to use curved arrow to indicate electron movement in the reaction. In this case our nucleophile is Br2. I was wondering why one Br molecule is more electronegative than the other one, as shown in the answer key. Thank you!

Miya Eberlein 1J

How can we tell when a reaction is fast, or when it is too slow to be important? How can we tell which step is slow?

Miya Eberlein 1J

Where did the value 0.34V come from? for the standard cell potential of the anode. is there an equation we're supposed to use? thank you!

Miya Eberlein 1J

how do we determine which half-reaction would create the largest voltage? does it stem from the g= -nFE equation?

Miya Eberlein 1J

i was just wondering, when solving for K, why the product concentration is 2x and not just x? thank you!

Miya Eberlein 1J

can someone explain the oxidation half-reaction part of this example? I'm just confused about why C2 has an oxidation number of +3 when C usually has an oxidation number of 4.

thank you

Miya Eberlein 1J

For balancing half reactions in both acidic and basic solutions, balance the elements that are not H or O first. Then balance the O atoms by adding H20. The balancing of these half reactions differ in this next step; in acidic solution, balance H by using H+. In basic solution, balance H by using H2...

Miya Eberlein 1J

Why does O4- have a charge of -2 in this example? I don't understand step 1 of this example. so basically how does oxygen have an oxidation number of -2?

Miya Eberlein 1J

Does anyone know where we can find the value to "atomize 1 mol C" for this problem? I don't see the same 717 kJ/mol value in appendix 2a or anything

Miya Eberlein 1J

Can someone help clarify #65 for me? We're trying to get to the equation N2 + 5/2 O2 --> N205 but at the end of the problem the solution is to subtract twice the enthalpy of NO from the formation of N205 because we don't need it... but we don't have N2 in the equation. Do we not need it because we w...

Miya Eberlein 1J

Where did the Cv,m value of 12.47 J/K*mol come from in Step 2 of example 9.5? Is that something we can look up or was it calculated somewhere..?

Miya Eberlein 1J

Hi, self test 9.4A asks to calculate the change in entropy from 20.00 bar to 5.00 bar. Why do we ignore the bar in our calculation and continue to use the gas constant 8.314 J /K*mol instead of the .08314 L. bar/K*mol?

Miya Eberlein 1J

Can someone help me with self-test 8.9A on page 244? I converted the number of grams of benzene, 39.1 g, to its molar mass. I then found that there are 2 mols of benzene in the sample and multiplied that by the amount of heat to get 30.8 kJ mol, even though the answer should be in kJ per mol.

Miya Eberlein 1J

In question 8.27 we're presented with two different pressures, one from the calibration of a piston and the other for an irreversible expansion. When solving for work done for both reversible and irreversible expansions, how do we know when to use which pressure?

Miya Eberlein 1J

Why does HF make a weak acid?

Miya Eberlein 1J

Why do we sometimes ignore the x in the denominator of the ratio of concentrations and sometimes we keep it there, for when we are solving for x in the questions that ask to find the pH?

Miya Eberlein 1J

how can we tell if an acid is weak or strong?

Miya Eberlein 1J

When drawing the ICE box, how do you know when the change in partial pressure is positive or negative?

Miya Eberlein 1J

When calculating the equilibrium constant, can we use the pressure of one thing and the concentration of another, or do we have to convert them to one or the other?

Miya Eberlein 1J

What are the trends for the periodic table with regards to their charges? Like how the row next to the noble gases are all negative 1, what are the trends for the rest of the table?

Miya Eberlein 1J

Does anyone know why for Nitrogen and below, the sigma p orbital is located above the two pi orbitals, but it moves to above the pi orbitals for oxygen and above? this was probably mentioned in class but I was just wondering out of curiousity!

Miya Eberlein 1J

I'm having trouble with a problem from chapter 3 number 87. We're supposed to determine which molecule would have the strongest bond, CF4, CCL4, or CBr4. The book says CF4 would have the strongest bond because it has the shortest bond, but this is an exception to the electronegativity argument. C an...

Miya Eberlein 1J

I'm confused about something in the course reader on page 67. When making a structure of a polyatomic species, the example used (NH4)2SO4, and it has 9 valence electrons. how do we know that its minus 1 e or (NH4)+? why does that happen? same thing with the SO4, how do we know its SO4 minus 2 electr...

Miya Eberlein 1J

The first orbital, the s orbital, can hold two electrons at most. Every shell after the first can hold up to eight electrons. One can tell how many valence electrons an element has by taking its atomic number and seeing how many electrons are left over from the first 2 electrons plus 8 each shell th...

Miya Eberlein 1J

Why is it okay to have an uncertainty of velocity less than the speed of light but not greater than? I know Dr. Lavelle went over this in class but the answer is still not clear to me

Miya Eberlein 1J

I didn't understand this topic until I read it over in the book, so I wanted to clarify what spectroscopy is in case anyone doesn't understand it. I understand spectroscopy to be a part of chemistry that deals with understanding how light is emitted or absorbed by certain substances. Scientists had ...

CHEMISTRY COMMUNITY

Search found 29 matches

Residual entropy

Comparing heat capacities in Final 2011

question 4.31 in the Intro to Organic Chem book

question 4.25 in ochem book

Slow reaction vs fast reaction

help with midterm 2012 q 7A

midterm 2011 question 6

2011 midterm q4

example 14.1

Re: Balancing redox reactions

Help with chapter 14 example 14.1

problem 8.67 b

Homework problem 8.65

help with example 9.5

Help with Self test 9.4A

Self-Test 8.9A

homework 8.27

Weak acid

Solving for x in calculating pH questions

Acids and bases

Drawing ICE box

Calculating equilibrium constant

Naming

Molecular orbital order

Strongest CX bond, where X is a halogen

Structures of Polyatomic Species

Re: Valence Electrons

Heisenberg's Indeterminacy equation

Spectroscopy