Tuesday, 12-15-09
Road Salt
&
Electrolytes
OPENER AT TOP OF BLUE SHEET:
- RECAPPING THE GOOD & BAD OF
SPORT DRINKS
TODAY’S OBJECTIVE
Students will compare conductivity between
sport drinks and stream water containing
road salt to identify safe levels of
electrolytes in both substances.
HOMEWORK
Please write in your
planner:
bring in small unopened
drink of juice to test
Key Word Recap
 A measure of how a material or fluid
can conduct electricity is known as
__________________.
 A dissolved chemical in blood or
water containing salts, acids or
bases is known as an
__________________.
What’s The Connection ?
Today we’ll compare
what happens to
your blood when
You drink Gatorade
and what happens
to water quality
when road salt
floods into a stream
Can TOO MUCH of a GOOD THING turn out BAD? Let’s investigate…
The Electrolyte
Connection
 Please read silently the half sheet article
 Complete the follow-up questions by
writing in the missing terms from the article
Storms, Road Salt & Streams
 Describe on your paper how the 3 pictures relate
 After the next rainstorm, what might happen to the
electrolyte levels in the stream water? Why?
Real Life Comparisons
What electrolytes can do for you
(measured with conductivity in uS/cm)
When they’re GOOD
When they’re BAD
0
200
250
300
= distilled water
= your blood level
= safe drinking water
= acceptable stream
(when testing blood/urine…
+200 = dangerous levels)
+300 = “hard water”
+500 = polluted stream
??
= your sport drink
?? = your stream sample
2000= lethal injection
So what’s a
“safe” electrolyte level?
Four-year comparison of Chloride
concentrations at Gwynnbrook
IN WINTER…
2004
2005
IN SUMMER…
2006
IF LEVELS DROP
TOO LOW, THE
STREAM
GOES ON “IV”
1000.00
100.00
10.00
Weekly sampling data by BES researchers
12/7
11/7
9/7
10/7
8/7
7/7
6/7
5/7
4/7
3/7
2/7
1.00
1/7
mg/L expressed in
Logarithmic scale
TO A STREAM,
THIS IS A LETHAL
INJECTION OF ROAD
SALT WASHOFF
2003
10000.00
Conductivity
Lab Procedure
1. TURN TO BACK OF YOUR LAB SHEET
2. FOLLOW EXAMPLE ON SCREEN
3. TEAMS OF 3 EACH, 1 PER STATION
NEW TEAM LEADERS ARE…?
Reporting in:
What did you discover?
1. Each team leader sends up ONE
sample
completed chart to show on the screen.
2. One member from each team explains
results shown on chart
3. Then we’ll move to the CLOSER
(on back of the half sheet)
And tomorrow, we can…
Test & compare conductivity
of something SAFE you bring in:
 Juice or Milk
 Your favorite sports drink or soda
 NOT cleaning items/household chemicals