What is a “Run-On
Statement?”
What is a run-on statement?
If we were to find the average of two
numbers, 24 and 26,
we would find the sum of 24 and 26 and
then divide the sum by 2.
If we set this up as follows, can you see
anything wrong with this?
24 + 26 = ______
50
= 25
2
24 + 26 is equal to 50
but is not equal to 50/2.
Be careful of writing run-on statements when
you determine empirical formulas in this
manner:
 1 mol C  4.104 mol C
49.30 g C 
= 1.499 mol C x 2 = 2.998 mol C
 =
2.737
 12.01 g C 
 1 mol H  6.845 mol H
6.90 g H 
= 2.50 mol H x 2 = 5.00 mol H
 =
2.737
 1.008 g H 
 1 mol O  2.737 mol O
43.80 g O 
= 1.00 mol O x 2 = 2.00 mol O
 =
2.737
 16.00 g O 
What is wrong with the setup shown above?
How to avoid run-on statements
When I first introduced the method of
determining empirical formulas, I specified that
it would be wise to set up with vertical columns
thus:
 1 mol C 
 1 mol H 
49.30 g C 
:
6.90
g
H



12.01
g
C
1.008
g
H




4.104 mol C
6.845 mol H
:
2.737
2.737
1.499 mol C
: 2.50 mol H
2.998 mol C
: 5.00 mol H
Ans. C3 H5 O2
 1 mol O 
: 43.80 g O 

16.00
g
O


2.737 mol O
:
2.737
: 1.000 mol O
: 2.000 mol O
This setup does NOT contain “run-on” statements.