CBE 546 Exam II - Partial Oxidation,
Hydrogenation And Petroleum Refining
Exam Questions And Answers 2025
For acidity, what are two ways to universally measure acidity? What is dG a
measure of? The higher the PA, the stronger the ______. Which is stronger
base:pyridine or NH3? A high conjugate anion PA is a measure of a
__________. - How do we quantify Bronsted acidity? Can measure the the
heat of solution from aqueous to gas that is independent of the base. The
proton affinity can be measured as well (PA). dG from heat is a measure of
gas basicity (GB). To elaborate, the higher the energy for PA, the stronger
the base. Pyridine is a stronger base than NH3, and propene is weaker
than both pyr and NH3.
,Terms in this set (100) Q&A
For acidity, what is the scale used to resemble pH for non aqueous
systems? How is it calculated? For what systems should this NEVER be
used? How is it measured? - Scale designed to look like pH was made as a
result of comfort. Hammett Acidity scale is H0=pK+log[A]/[HA]. Hammett
acidity used with solids (DO NOT USE), take a series of weak bases and
see which get protonated by solid acid.
For acidity, why is the slope 1 between NH3 and py? What is this reason a
direct measure of? What are ways to measure site concentration without
assuming [H+]=[Al3+]? Why is TPD not a good method for this? - Slope is
1 for strong base due to interactions between B and the pore which are
stronger than in a liquid and a result of the direct strength of the base.
An incorrect method is NH3 TPD which NH3 is adsorbed, flushed, ramped,
and then strength with Tp gives conc, but this is incorrect because this
method shows that CaO is a stronger acid that H-Y zeolite, which is
logically and practically not true.
One proper method is IR of pyridine, where the base vs conj acid have
different IR ring stretching modes.. 1550cm-1 band doesn't exist for base.
Quantified using Beer's law. IR is simply looking through sample with IR
light shining, and with the exponential function for I. It has also been shown
that despite having different cat abilities, that similar NH3 adsorptions have
been measured. (H-ZSM-5 and H-Fe-ZSM5).
Another method of measuring acid site [] is through alkyl amine TPD,
where propyl NH2 reacts with H+ to form C3H7NH3+, which under
Hoffmann elimination forms C3H6+NH3+H+, and this TPD peak on the
, Terms in this set (100) Q&A
graph is clearly shown when this occurs, in which site strength appends on
composition framework.
For alkylation, what is presently used as the cat? Why is the material
designed the way it is? What does having a Si in aluminophosphate group
allow for? - At UDP~1990 and to present, they use a small pore zeolite like
SAPO-34 (Silicon Aluminum Phosphate) to form CHA (chabozite). Having a
small opening but big cavity allows for the limitations of alloying only
desired product. Don't forget that the changes are balances on a zeolite,
where having a Si group substituted in a aluminaphosphate allows for a
bronsted acid site.
For ammoxidation, what is the catalyst for propane reactant? What can Te
be subbed with? Applications of acrolein? Cat diff from acrylonitrile? What
reaction type is used? What needs to be added to process for acrylic acid
production from acrolein? - The Catalyst for them is MoVNbTeOx
(crystalline, this eq not stoich). Te may be subbed with Sb. Propylene to
acrolein can be used to make allyl alcohol. Conditions, catalysts are very
similar (except no NH3 in feed) For acrolein, use shell n tube reactors, with
Molten salt for temp control. Acrylic acid - start with acrolein, use second
reactor (similar catalyst, lower T)
For ammoxidation, what is the catalyst? What happens/is formed if NH3 is
not present? - The catalyst is Bi2O3-MoO3 (bismuth molybdate) In
absence of NH3=> C=C-C=O is formed (acrolein) and can further form
acrylic acid.
For ammoxidation, what is the class cat? What is the argument for Bi's
purpose? What can be substituted for Bi and Mo? GIve the overall
chemical reaction of ammoxidation. - Classical work suggest catalyst was
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Schoolflix. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £13.40. You're not tied to anything after your purchase.
