***October 2013 - Chemistry***

<p>**** i got the reaction mechanism wrong :(</p>

<p>That means that there are 3 T,T,CE.</p>

<p>As we might expect from the periodic variation of electronegativity, the oxidizing power of the halogens decreases in the order F2 > Cl2 > Br2 > I2. Fluorine is such a strong oxidizing agent that it can react with water
but doesn’t this mean NOT ALL of them are good oxidizers?</p>

<p>As we might expect from the periodic variation of electronegativity, the oxidizing power of the halogens decreases in the order F2 > Cl2 > Br2 > I2. Fluorine is such a strong oxidizing agent that it can react with water
but doesn’t this mean NOT ALL of them are good oxidizers?</p>

<p>(All these is what I THINK it said)
The electrolysis of water is endothermic BECAUSE when water is turned into hydrogen and oxygen, it decreases the entropy of the system. T,F
CH4 has a geometry of square planar BECAUSE each C-H bond in CH4 is identical and the same length. F,T
Na, K, and Li has the same chemical properties BECAUSE they all have the same number of valence electrons T,T,CE.
H2O is a linear molecule BECAUSE the O-H bond is polar. F,T.</p>

<p>i don’t think it said isolated</p>

<p>I don’t think that water in a container TF question said anything about boiling or systems in isolation. I think it went something like this:</p>

<p>When water evaporates from the surface of an open container the average KE is decreased BECAUSE the molecules in the vapor phase had a higher KE than the liquid phase and carried heat with them. Something like that.</p>

<p>I can’t believe there were almost no redox or electrochem questions -_- I prepped so much for those</p>

<p>Some utter nonsense here. I dont know if college board rewards marks for these answers but its non sensical.
The catalyst question is not ttce
The catalyst is not consumed -true
It doesnt affect reaction mechanism - true
There is no relation or cause/effect here.
And yes vapourisation indeed increases entropy (randomness, geniuses)
STOP asserting opinions as facts, its science ******.</p>

<p>@roxy there always seems to be a concept that’s barely tested. In June it was organic chem. not a single question.</p>

<p>@Psych1 Reaction mechanism is changed ( Reaction takes place in multiple steps of lower activation energy ).</p>

<p>CH4 has tetrahedral geometry. Square planar has sp3d2 hybridization so it cant be 4 bonds.</p>

<p>■■■■■ aunty…
Reaction profile changes… I doubt if mechanism does. Regardless, how is it ce then?</p>

<p>Well ■■■■■ aunty, you need to realise how chemical reactions proceed. The molecular interactions leading to the reaction called the mechanism will take place regardless of the catalyst. The catalyst merely provides a host region for these interactions with lower activation energy and speeds reactions up. It will be poor on college boars apart if it rewards marks for that explanation. As a test taker i can only think logically</p>

<p>Psych the reaction mechanism is the means by which the reaction happens, which also can be considered the number of steps required in the reaction, and it absolutely does change so it should be TF</p>

<p>Well i dont see how that works. But alright. I never thought there was ce there.</p>

<p>@Psych1 if you are correct then ill be really happy ( i thought the same as you during the test ).</p>

<p>But… [SparkNotes:</a> Reaction Kinetics: Reaction Mechanisms: Mechanisms of Chemical Reactions](<a href=“http://www.sparknotes.com/chemistry/kinetics/mechanisms/section1.html]SparkNotes:”>Reaction Kinetics: Reaction Mechanisms: Mechanisms of Chemical Reactions | SparkNotes)</p>

<p>:'(</p>

<p>Someone tell me this reaction mechanism question, Ill clear it up once and for all.</p>

<p>was it?
A catalyst is not consumed in a chemical reaction BECAUSE the reaction mechanism has changed.</p>

<p>Please refer
[Chemical</a> Catalysis - Mechanism and Theory | Catalysts in Chemical Reactions, Institute of Theoretical Chemistry](<a href=“http://itchem.com/catalysis]Chemical”>http://itchem.com/catalysis)</p>

<p>Catalysts only change the physical aspects of the reaction as we can infer.</p>

<p>Well psych1 that is a valid article but many sources seem to say otherwise. Just to clarify… I put TT with no CE as my answer, so I’m hoping you’re right. However, based on the level of chemistry that was being tested on the SAT II, I believe that the mechanism of reaction is affected according to CB.</p>

<p>@Cheesy18 that is not a valid reason…</p>

<p>T,T, Not CE</p>