1. Salinity Calculations
Finding salinity (% & ppt)
Converting from % to ppt
Finding amount of salt in saltwater
Making water with specific salinity

2. 1. Finding % and ppt (o/oo)
To find o/o, divide the part by the whole, then multiply by 100.
To find o/oo, divide the part by the whole, then multiply by 1000.
If 38 out of 50 students passed a test, what percent passed? How many parts per thousand passed?
7.0 lbs of saltwater contains of 1.5 lbs of salt. What is the salinity in percent & parts per thousand?

3. 2. Conversions between % and o/oo
To go from % to o/oo, multiply by 10 (or move decimal one to right)
To go from o/oo to %, divide by 10 (or move decimal one to left)
1.3 % = _____ o/oo
0.265 % = _____ o/oo
2.77 % = _____ o/oo
7.00 o/oo= _____%
6.55 o/oo= _____%
55 o/oo= _____%

4. 3. Finding amount of salt in water
Using %
Multiply weight by % over 100
Using o/oo
Multiply weight by o/oo over1000
On average, ocean water has a salinity of 3.5%. How many lbs of salt would there be in 60 lbs of ocean water?
If a 250 lb sample of salt water has a salinity of 45 o/oo, how many pounds of salt are dissolved in it?

5. Making Water with certain salinity
Find out how much of the water is salt (as in previous slide). That is how much salt you need.
Subtract the amount of salt from the amount of salt water to find the amount of water you need.
Make 25.0 grams of salt water with a salinity of 45 ppt.

6. Today you are going to… complete the salinity lab.
So you can… calculate salinity problems and understand the effect salinity has on density and organisms.
You’ll know you’ve got it when…you can
Create 3 layers of water with different salinities
Answer the lab questions

7. Lab! Everyone in your group has a job
Salt master – get salt, clean up
Water master – get water, clean up
Mix master – label test tube, mix water & add food coloring, clean up
Place your finished test tube in the sand
When finished:
Clean up & return to your lab desk. I will give you a lab conduct grade then.
Work on the Post Lab Questions
Lab conduct will be graded throughout period

8. Lab Conduct Stay in group, at one desk Actively contribute
One person get water whilst another gets salt
Get low when reading graduated cylinder
Be respectful of equipment
Be careful with glassware – don’t clang it
Don’t set round things on table…they’ll roll off!

9. Lab Conduct Stay in group, at one desk Actively contribute
One person get water whilst another gets salt
Get low when reading graduated cylinder
Be respectful of equipment
Be careful with glassware – don’t clang it
Don’t set round things on table…they’ll roll off!

10. Procedure Mass salt Measure water Dump salt in little test tube
Tare cup
Measure water
Get low!
Dump water in little test tube
You may have to use grad. Cyl. Twice
Dump salt in little test tube
Cover with thumb & carefully shake to mix
Add food coloring (not much) & swirl
Carefully transfer to large test tube

14. Supplies 1 large test tube 1 small test tube
1 pipette (use to get exact amounts of water)
Empty paper cup to measure salt in

15. When finished
show me your layers & give me all group members’ papers to grade layers
Rinse both test tubes out & put them upsidedown in containers by sink
Rinse pipette & put it in your beaker. Put it by the sink.
Dump any remaining salt into the sink & put your paper cup there.

16. Salinity of Ocean Water Worksheet
On average, ocean water is 1.19% calcium. Convert this to ppt.
If there are 306 quintillion pounds of water in the ocean, how many pounds of calcium are there?

17. In 1800 pounds of water of seawater, there are 20. 5 pounds of salt
In 1800 pounds of water of seawater, there are 20.5 pounds of salt. What is the salinity of the water? (% and o/oo)

18. Finding weight or mass (lbs or kg) using percent (%) or ppt (o/oo)
On average, ocean water has a salinity of 3.5%. How many lbs of salt would there be in 60 lbs of ocean water?
If a 250 lb sample of salt water has a salinity of 45 o/oo, how many pounds of salt are dissolved in it?

19. Bell Ringer 11/14/13 – 3 min
Quietly read the “Salinity of Seawater Lab Info Sheet”.

20. Bell Work – 3 minutes Take out your:
Salinity of Seawater Lab Info Sheet
Salinity of Seawater Lab.
Work on the Salinity Lab Problems.
Must have # 3, 8-10 finished to start lab!
# 8, 9, & 10 refer to numbers 6, 4, & 3.