Chemistry Lab Report 1 PDF

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Experiment 1

Basic Laboratory Operations

CHEM-1111-59 The University of Texas Rio Grande Valley Fall 2018 Ning Wang Emilio Molina Juan Guiterrez & Josue Ivan Hernandez

OBJECTIVE: -

The objective in this experiment was to create an efficiently burning nonluminous flame by adjusting the gas control valve and air control valve on the Bunsen burner. Also to develop skills to properly operate a balance efficiently and determine the density, mass, and volume of unknown substances. Including with these skills, the development of how to use a pipet correctly must be needed to succeed in this laboratory experiment as well.

INTRODUCTION: -

In this lab we learned about techniques that will be used repetitively throughout our lab manual. We used a Bunsen burner, which uses methane (CH4), in order to produce an efficient flame. Methane is considered a hydrocarbon because it made up both carbon atoms and hydrogen atoms. When an adequate amount of oxygen is given, the methane will burn with a nonluminous flame. In the same way if an inadequate amount of oxygen is present in the methane the flame it will heat and produce a light that will be considered incandescence. Basically, When the burner was properly lit, we distinguished which part of the flame was the “hot” and “cold “zone. After taking data of the Bunsen burner, we will proceed with measuring the unknown liquid and solid substances, by properly handling the material needed, such as a pipet and balance. When measuring the liquid in a graduated cylinder we started to calculate the density it contained with the unknown liquid substance by itself and after including the solid material combined. While perfectly following the instructions of the lab manual for this experiment, data had to be recorded to analyze what changes or effects occurred in the many trials that were conducted while successfully realizing this experiment.

1. When the gas control tube is closed slightly then amount of the fuel is less but

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the amount of the air (O2) is more therefore it burns well with blue color flame this flame have high temperature. Therefore pale blue color flame means it have higher temperature because of the complete combustion of the fuel. When the air control value is slightly closed then the air needed for the combustion is less therefore the flame burns with the yellow color and flame is soothe (this flame has low temperature). The fuel for candles is the wax as well as the oxygen (that is why it is luminous). The candle experiences this type of flame because there is an insufficient amount of oxygen being burned. If a solid is not completely submerged, it will make the reported density higher. This is because the volume of liquid displaced will be minimalized, and thus we will be dividing the mass by a reported smaller volume. If water droplets stick to the inside of the pipet it will cause the volume of the water to be a lower value then what the pipet is calibrated to, the density of the water will be higher. This is because you have the same measured amount of mass, but the volume will be lower, because part of it remains on the cylinder walls. When the mass is the same and the volume is lower, you will have a greater density. IF some of the liquid evaporated between time delivered and the time its mass is measured, it will have a lower mass, meaning a lowered calculated density.

CONCLUSION: -

To conclude, this lab was to learn the basic laboratory techniques and apply them to the final procedure to determine the identities of our unknown substances. As

our first lab. In mi opinion, I believe it was very successful because we developed the ability to handle a variety of experiments and comparing results has allowed for everyone to refine techniques they already knew, as well as improve. Most of the results were written down for data which, were precise and measured more than twice. We took our precautions and double checked are work to be the most accurate as possible. I enjoyed this lab, because it was a refresher that will allow me to be successful on the many experiments that are about to come....