Thanks for saving my grades good sir. I swear Khan academy and other "famous channels" are so overrated. Best online tutoring video, with the zombies and all. Amazing.
i have to say that this video was tremendously helpful. i agree, rate equations are just one of those things you have to just know. anyways i have my paper 1 and 2 tomorrow and this video really helped. perhaps ill see one of those equations tomorrow. thank you for all your hard work, you're a great teacher, please continue to make these for the benefit of kids around the world
LOL ''IDK HOW TO TEACH THIS'' but u did teach me!! my teacher knows or at least he think he knows and I never understood! So thank you :) 5 days away from exams ugh! Thanks again I wouldn't be able to find a better way to revise. I love you Mr.Thornley!
But the syllabus says "Only examples with one- or two-step reactions where the mechanism is GIVEN will be assessed." So we don't need to come up with the mechanisms?
Hello Sir! I did the devilish nitrogen question myself and got the two-step mechanism: N2O --> NO + 0.5N2 NO + N2O --> 1.5N2 + O2 (R.D.S) Can this be a possible answer as well?
Hello Mr. Thornley. I just have a quick question (video was very helpful by the way). I understand that when writing the rate expression, you have to make sure the concentrations used in the expression have to be of reactants in the overall equation, but what if the first step is the rds with a two reactants, one as a catalyst and the other as a reactant in the final equation? Do you write the expression using the concentration of the catalyst even though it isn't in the overall equation? Hope this question makes sense haha thanks either way!
Sometimes the catalyst is in the rate equation (the IB asked a question on that once). So only the reactants can appear in the rate equation, and a catalyst is considered a reaction.
then i think rate=k[catalyst][reactant] . Even though the catalyst gets "cancelled out" in the equation it appears in the rate equation. The IB have only asked this once and we were all surprised !
![R2.2.6 Rate constant, overall order of reaction, order of reaction [HL IB Chemistry]](http://i.ytimg.com/vi/9sMFJMuZzmg/mqdefault.jpg)
![R2.2.6 Rate constant, overall order of reaction, order of reaction [HL IB Chemistry]](/img/tr.png)
![R2.2.7 Energy Profiles and Mechanisms [HL IB Chemistry]](http://i.ytimg.com/vi/V_z-mhDsMks/mqdefault.jpg)
![R2.2.10 Sketch graphical representations for 0,1st 2nd order reactions [HL IB Chemistry]](http://i.ytimg.com/vi/urVl4TJRlpc/mqdefault.jpg)
![16.2 Arrhenius Equation k1,k2,T1,T2 [HL IB Chemistry]](/img/n.gif)
Thanks for saving my grades good sir. I swear Khan academy and other "famous channels" are so overrated. Best online tutoring video, with the zombies and all. Amazing.
+Vatsalya Saini I have actually taught chemistry to students for years - this helps!
pro trick : you can watch series at Flixzone. I've been using them for watching loads of movies these days.
@Nasir Salvatore yup, have been watching on flixzone for months myself :)
i have to say that this video was tremendously helpful. i agree, rate equations are just one of those things you have to just know. anyways i have my paper 1 and 2 tomorrow and this video really helped. perhaps ill see one of those equations tomorrow. thank you for all your hard work, you're a great teacher, please continue to make these for the benefit of kids around the world
can i hire u on behalf of my school lol
LOL ''IDK HOW TO TEACH THIS'' but u did teach me!! my teacher knows or at least he think he knows and I never understood! So thank you :) 5 days away from exams ugh! Thanks again I wouldn't be able to find a better way to revise. I love you Mr.Thornley!
Your videos are the best I've seen so far. Thanks a lot!!! Hope you'll complete all of the sections. Cheers!
Hello! Thank you so much for all the videos. You are the best youtube teacher for ib chemistry! I also suggested you to my friends :)))
at 4:20, couldn't the second example work? What if we found experimentally that the coefficient for [B] is 0 and 2 for [A]?
For the medium example, rate=k[A][A] was simplified to rate=k[A]^2. Does that then make A second order?
But the syllabus says "Only examples with one- or two-step reactions
where the mechanism is GIVEN will be assessed."
So we don't need to come up with the mechanisms?
You can never assume that the coefficients are the exponents - but they may end up as them.
eg If the reaction mechanism is only one step
Love your videos!Just wondering, the part with the zombies and the station... is that a video game? Where is that from?
Garrys Mod
for the 2-step mechanisms you wrote (with N2O -> N2 + O / N2O + O -> N2 + O2), I thought oxygen is diatomic so it should always come in pairs?
Will the following mechanism also work?
2N2O -> 2NO + N2
2NO + N2 -> 2N2 + O2
Where the first step is the rate determining step?
The o2 has to break at some stage to make a new molecule. Monatomic oxygen is very unstable and reactive - so this is a very short lived specie.
@Richard Thornley
Is this correct:
A + B -> AB
AB + C -> ABC
A + B + C -> ABC
Nice work Mr T.
For the final problem, couldn't the second step also be the RDS???
Kind Regards
Hello Sir!
I did the devilish nitrogen question myself and got the two-step mechanism:
N2O --> NO + 0.5N2
NO + N2O --> 1.5N2 + O2 (R.D.S)
Can this be a possible answer as well?
They have asked in the recent past for mechanisms.
Hello Mr. Thornley. I just have a quick question (video was very helpful by the way). I understand that when writing the rate expression, you have to make sure the concentrations used in the expression have to be of reactants in the overall equation, but what if the first step is the rds with a two reactants, one as a catalyst and the other as a reactant in the final equation? Do you write the expression using the concentration of the catalyst even though it isn't in the overall equation? Hope this question makes sense haha thanks either way!
Sometimes the catalyst is in the rate equation (the IB asked a question on that once). So only the reactants can appear in the rate equation, and a catalyst is considered a reaction.
Richard Thornley Awesome, thanks so much!
then i think rate=k[catalyst][reactant] . Even though the catalyst gets "cancelled out" in the equation it appears in the rate equation. The IB have only asked this once and we were all surprised !
yup
What software do you use for the demonstrations?
so if its the rate determining step, the coefficients become the exponents?
yup
This helped me so much
why do you assume that the reactants are always of first order in the rate equation
RDS= the step with the highest energy transition state! Not the step with the highest activation energy (Ea)
Well...
soooo helpful thanks
Thankkkkkkkkkkkkkkkkkkkkk you !!!
Would this one work for the evil one?
N2O+ N2O --> N2+ 2NO(rds)
NO + NO --> N2 + O2
5 years late by N2 doesn't cancel out
Do you have any methods to let students contact you? (ex: email)
email is in the about section
i used to understand very little,coz most of time I end up wondering
Activstudio on an Activboard (plus Garrys mod)
"evil" hahaha
:)
u lost me at 3:11
:)