CHEMISTRY COMMUNITY

Emma_Green_2C

Cis is when the substituents are on the same side of a double bond and trans is when they are on opposite sides. This should be apparent on the line structure just by looking at it. Z corresponds with cis and E corresponds with trans. You determine Z and E by looking at the atomic number (whichever ...

Emma_Green_2C

The course reader answer has a 1 as the lowest number, while your proposed answer has a 2 as its lowest. Since 1<2, the course reader is correct. I think it's not necessarily about having overall lower numbers, it's just having THE lowest number.

Emma_Green_2C

Gauche is when the large atoms are staggered adjacent to each other (60 degrees) and anti is when the large atoms are opposite each other (180 degrees). Both are staggered but the names gauche and anti tell you the different energies of the conformations. Anti is the most stable (lowest energy) and ...

Emma_Green_2C

I think you use hydroxy when you are treating the -OH group as a substituent but you would only do this when there is more than one functional group. In 9B there was also a ketone in the first structure and a carboxylic acid in the second structure.

Emma_Green_2C

You can use any experiments; they are independent of each other.

Emma_Green_2C

If I am understanding your question correctly, I believe the negative sign is used when calculating the rate of the reactant because the concentration of the reactant decreases as it becomes product.

Emma_Green_2C

For #8, I don't understand why the reaction will not be spontaneous at any temperature. Please help! Thanks! If you plug in the given values into the equation deltaG= deltaH-T*deltaS and set delta G to zero, you will get a negative number for the temperature (-985.5K). You cannot have a temperature...

Emma_Green_2C

I noticed Dr. Lavelle answered this question in another post. He just used the volumes and ignored the pressures given in the problem. The ratios of the pressures and the volumes should actually be the same, so you could use either V2/V1 or P1/P2 in the equation (since pressure and volume are invers...

Emma_Green_2C

I'm also not completely sure, but I solved it the same way as Joseph.

Emma_Green_2C

Specific heat capacity and molar heat capacity are the heat required to raise the temperature of "1 gram" and "1 mole," respectively, by 1 degree Celsius. In contrast, heat capacity is the heat required to raise the temperature of "an object" by 1 degree Celsius. Dividi...

Emma_Green_2C

Yes and you would also have to convert kJ to J.

Emma_Green_2C

I think my TA said that if the Ka value is 10^-5 or smaller then you can assume x is zero. So under that circumstance I'm pretty sure you would be safe making that assumption on the final.

Emma_Green_2C

The basic idea is that atoms of different elements have different electronegativities and exert pulls of differing strengths on the electrons. In a bond, the less electronegative atom will have a partial positive charge while the other atom will be slightly negative. If two different elements are bo...

Emma_Green_2C

The chemical equation is HSO4- + H2O double arrows H3O+ +SO42-. You just use one equation for each part of this question and calculate the pH using the Henderson-Hasselbalch equation for the various concentrations of acid and conjugate base.

Emma_Green_2C

Sulfuric acid is polyprotic so there are two deprotonizations. The first time, H2SO4 is completely ionized into HSO4- and H3O+. Since the ionization is complete, the concentration of HSO4- is 0.15M and the concentration of H3O+ is 0.15M (same concentration as H2SO4). The next ionization is incomplet...

Emma_Green_2C

I think you can use the Henderson-Hasselbalch for #5 (as in #7), but it would be easier to use an ice table because this question only asked for the concentration of hydronium ions instead of pH. This means if you use the H-H equation you will have to convert from pH to [H+] which is an additional s...

Emma_Green_2C

When you are asked to give the formal charge for each atom within a Lewis structure, you just calculate that using the formal charge formula. You don't need to give an average. As for the second half of your question, the problem will probably indicate whether multiple Lewis structures (resonance) a...

Emma_Green_2C

An element has multiple ionization energies in the sense that the first ionization energy is the energy it takes to remove the outermost electron (ex. from Na to Na+). Then the second ionization energy is the energy it takes to remove another electron (Na+ to Na^2+), the third ionization energy is t...

Emma_Green_2C

I'm from Canyon Point A1 and I'd love to join sometimes! Is there a meeting place/time?

Emma_Green_2C

When making an intermediate calculation in a problem with multiple steps/operations, I usually underline the digit of the last sig fig but leave the number unrounded. It helps me to keep track of the number of sig figs from step to step without losing accuracy by rounding during intermediate steps.

CHEMISTRY COMMUNITY

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