Sea Water Distillation Lab Report

Seawater Investigation

Introduction

Distillation is the process of purifying a liquid by heating or cooling (dictonary.com, 2018). In this experiment seawater is to be separated through the distillation process. The mixture of seawater is heated in a flask. The water then evaporates and travels through the Liebig condenser where it is cooled down and turned back into a pure liquid and drip into the beaker.

Aim: to separate seawater using distillation and confirm the identity of the of the major ionic compound present in seawater

Materials List 1: Two retort stands and clamps, tile, Bunsen Burner, gauze mat, pear-shaped flask, distillation kit, beaker, two tubes, matches

Materials List 2: Tripod, gauze mat, tile, Bunsen Burner, evaporating

Silver nitrate was added to the evaporated water to show the purity of the water. The silver nitrate was clear in the water therefore indicating that the water was pure. This can be seen in figure 1 as the water on the left is clear and the water on the right turned white indicating that there was salt present.

The amount of seawater present before the evaporation began was 21.34g. After the experiment the amount of salt left over was tested by weighing the evaporating dish with the remaining salt in it then collecting necessary salt for the flame test and washing the dish to weigh again. The weight of the evaporating dish with the salt was 56.11g and once weighed without salt it was 55.4g meaning that the amount of salt present was 0.71g. The percentage of sodium chloride present in the seawater was 3.33%

During the flame test the salt which was left in the evaporating dish was collected onto a pop stick. The Bunsen burner was turned on and the pop stick was placed under the flame. The flame turned orange indicating that sodium was present.

The amount of water collected through the distillation process was small as there was too much seawater used and therefore it was unable to fully evaporate. If the water had been evaporated the results would have been clearer that the water was pure.

In the second part of the experiment the water was tested before hand to ensure that the water was seawater using silver nitrate and then later tested to find out what ionic compound it had in it, sodium chloride. Glass bead were placed into the pear-shaped flask to control the boiling water. Without the glass bead the risk of the water spurting up and going down the tube increases, decreasing accuracy of the distillation.

There is always improvement to be made in an experiment and if this experiment was to be conducted again less water would be used to in the distillation process. This would quicken the process and create more accurate results. The possibility of the equipment not being clean and containing salt water in it could affect the results of experiment. If any seawater was found in the beaker being tested with silver nitrate the water would not be as clear as it was therefore being