Lec 14 - A catalyst reduces the activation energy for a...

1
1
A catalyst reduces the activation energy for a
reaction from 27.0 kJ/mol to 2.0 kJ/mol. By what
factor is the rate accelerated? Assume the
frequency factor A does not change, and the
temperature is 300 K. R = 8.314 J mol -1 K -1
A) 2.25 X
B) 22.5 X
C) 225 X
D) 2,250 X
E) 22,500 X
a
RT
E
Ae k


2
Could also be given the rate constants and T and
be asked for the change in activation energy.
 
cat wo
cat wo
wo cat
wo
cat
a
E E
RT RT
E
RT
E
RT
E
RT
E
RT
E
RT
E
wo
cat
RT
E
e e
e e
e
e
k
k
Ae k
 




 
















 

1
Or given k
cat
, k
wo
, T, and E
wo
and asked for E
cat
.

2
3
HCl(g) + H
2
O(l) H
3
O + (aq)
+
Cl - (aq)
Chapter 16 Acids & Bases
The Brønsted-Lowry Definition

An acid is a chemical species that donates
a hydrogen ion (proton, H + ) in a chemical
reaction.

A base is a chemical species that accepts
a hydrogen ion in a chemical reaction.

Aqueous acid-base chemistry occurs in a
water solution or environment and often
involves water as a reactant or product.
4

The material scheduled for today was
covered in CHE 129 & 131.

Today’s PwrPt notes will help you review this
material. We may not cover it all in class.

First, let’s reflect on Exam 1.

What are the two overriding goals of this
course?

What are the two types of questions you
think most students found most challenging
on Exam 1?

What can be done to do better on such
challenging questions?

3
5
Course Goals

Master the concepts and procedures
in General Chemistry!