Salinity of Ocean Water
Recommended for grades 6–12.

Introduction
If you were to view the planet Earth from space, you would see that most of its surface is covered by water. Most of this is ocean water which cannot be consumed. Why can’t ocean water be consumed? The reason is that ocean water contains large amounts of salt, which make it undrinkable.
Salinity is a measurement of the saltiness or concentration of salt in water. Ocean water contains many different salts, but the most abundant is sodium chloride, also known as table salt. Sodium chloride makes up 86% of all the ions present in ocean water. Other salts that can be found in ocean water at significant levels are calcium chloride and magnesium chloride.
In this experiment, you will use a Conductivity Probe to measure the salinity of salt water. In Part I, you will measure the change in ocean salinity due to evaporation. In Part II, you will measure the change in salinity near the mouth of a river as it flows into an ocean.
Objectives
In this experiment, you will
- Measure salinity of water sample using Conductivity Probe.
- Determine the effect of evaporation on the salinity of ocean water.
- Determine the salinity change when a river flows into an ocean.
- Calculate salinity changes.
Sensors and Equipment
This experiment requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You may also need an interface and software for data collection. What do I need for data collection?
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
Note: The experiment preview of the computer edition does not include essential teacher information, safety tips, or sample data. Instructions for Logger Pro and other software (such as LabQuest App or TI handheld software, where available) are on the CD that accompanies the book. We strongly recommend that you purchase the book before performing experiments.
Standards Correlations
See all standards correlations for Earth Science with Vernier »

