Mock Fr

Date Performed: 17 Feb. 2015

Date Submitted: 04 Mar. 2015

Institution/Department:

Department of Mining, Metallurgical, and Materials Engineering

College of Engineering

Instructor: Ina Dela Fuente

The Determination of Moisture and Phosphorous Content from Fertilizer Sample using Gravimetry

E. M. Raguindin

The experiment aims to use gravimetric analysis to determine moisture content and phosphorous content of the fertilizer. Methods such as constant weighing, weighing by difference, and precipitation were used. Crucible tongs were used in handling the crucibles because moisture is a crucial part of the experiment. Moisture content is 1.26% which means the fertilizer has high purity. The phosphorous content of the sample is 4% and the phosphorous pentaoxide is 9%. The experiment proves to be successful because of a relatively low percent deviation of the Phosphorous from the theoretical value.

Introduction

Materials and Methods

Solution preparation was done first. These solutions were prepared quantitatively: 500 mL of 10% MgSO4•7H2O and three 500 mL of 2 M NH3 solution. For the next part of the experiment, crucibles were needed for drying the precipitate. It was then labeled and covered. The crucible was placed in the oven set at 110ºC. The hot crucibles were then transferred into a desiccator. For handling the crucibles, crucible tongs were used instead of bare hands because it will add moisture to the crucible, thus resulting in an error when analyzing the data. The crucibles were cooled for about 15 minutes, and then they were weighed using the analytical balance. After weighing, the crucibles were placed back in the oven for 30 minutes. Note that the covers for the crucible should be slightly open. After 30 minutes, the crucibles were again weighed. This process was repeated until a constant weight was obtained, or has a deviation of ±0.0002 to ±0.0003.

After a constant weight has been obtained, the fertilizer sample about 3.0 g was...