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.