Experiment 1 lab report PDF

Preview

Summary

Lab Report to first Ch204 experiment ...

Description

CH 204 – Introduction to Chemical Practice Experiment #1– Determination of Densities Cailey Montgomery Hunter Mitchell TA: Atreya Dey January 31st, 2018

Results & Discussion During this experiment the determination of the densities of Coke and Diet Coke was conducted. Density being the measure of mass per unit of volume, calculated by taking the total mass of an object or liquid and dividing it by the total volume. Different types of glassware were used to measure a certain amount of a substance into a beaker which was then weighed. The weight was recorded and used to calculate the density for each method of measurement. The initial mass of the first beaker was 23.373g and the second 22.111g. Each beaker has an increase of at least 5grams once the substance was added and weighed. Learning how to conduct experiments with accuracy and precision was also a major portion of the lab, accuracy, being how close a measured value agrees with the correct value. Precision on the other hand is how closely measurements agree with one another. When calculating the densities, having used 5mL as the volume for all the trials, Diet Coke had an average density of about 1.0g/mL-1.02g/mL while Coke’s averaged around 1.0g/mL-1.04g/mL for its density. The average density of the class data for Diet Coke was 0.99g/mL-1.04g/mL and for regular Coke 1.01g/mL-1.07g/mL.This proved the hypothesis to be true, that if the densities of Coke and Diet Coke were compared, the diet would be less dense. The different methods of measuring the coke also came into play, some methods of measuring the volume being more accurate and some being more precise. As seen in the Coke and Diet Coke table below, the measured values across the board were all measured precisely however accuracy between the weights was hard to determine. The Diet Coke weights differed from one another by no more than 0.200grams, this also being true for the regular Coke. Accuracy did come into play however when looking at the overall experiment, as Diet Coke is scientifically proven to be less dense than the regular and proved so. The purpose and objective of this experiment was to introduce scientific method correctly, demonstrating the importance of taking accurate experimental measurements, while also learning how to properly use lab equipment. Before the experiment was conducted, the prediction was made that if the densities of Coke and Diet Coke were compared, the Coke would prove to be denser due to the extra added sugars. This proved to be true as the data was further collected. Diet products are measured to be less dense versus the regular product because of the sweetener that is added to the beverage, not as much sweetener is added to diet products versus the original product. This applies to a variety of diet products across the board, as they all contain less sweetener’s. Different types of glassware were used, and this did influence the accuracy and precision of the measurements throughout the experiment. The pipette seemed to be the most accurate and precise form of measurement, measuring exactly 5mL of substance each trial. This also stood true for the measuring cylinder, as the measurements were equal each time. When looking at the equation for density, mass over volume, density and volume have an inverse relationship. Therefore, when the volume increases the density decreases in return. If the volume

CH 204 – Introduction to Chemical Practice Experiment #1– Determination of Densities Cailey Montgomery Hunter Mitchell TA: Atreya Dey January 31st, 2018 during the experiment had been doubled, the density values would have been split in half. This was concluded by simply following the mass over volume formula. Error throughout the experiment may have skewed the data such as simply not measuring accurately enough, the volume could’ve been a little over 5mL exactly or less. There also was the fact that the glassware was not washed properly before taking measurements, leaving leftover substances to affect the recorded measurements. Taking the weight of the beakers also had room for error, there could’ve been a possible mix up between the beakers, therefore recording data for the wrong beaker as well as mixing up of the substances themselves.

CH 204 – Introduction to Chemical Practice Experiment #1– Determination of Densities Cailey Montgomery Hunter Mitchell TA: Atreya Dey January 31st, 2018

Table 1:(Diet Coke Table) Initial Mass

Beaker 1

23.373g

Mass using graduated cylinder 28.454g

Volume

0mL

5mL

5mL

0

1.0162 g/mL

1.0 g/mL

V1:36.7mL V2:41.7mL = 5mL 1.0194g/mL

22.111g

27.245g

27.116g

27.279g

0mL

5mL

5mL

0g/mL

1.0268 g/mL

1.001g/mL

V1: 41.7mL V2: 46.8Ml =5.1mL 1.0133g/mL

Mass using pipette

Mass using Burette

26.416g

26.715g

Density of Beaker 1 Beaker 2 Volume

Density of Beaker 2

Mass using Pipette

Mass using Burette

28.373g

28.470g

(Table 2: Coke Table) Initial Mass

Beaker 1

21.222g

Mass using graduated cylinder 26.250g

Volume

0g

5mL

5mL

Density of Beaker 1

0g/mL

1.0056g/mL

1.0388g/mL

V1: 28.4mL V2:33.5 mL =5.1mL 1.0771g/mL

Beaker 2

22.010g

27.040g

27.206g

27.223g

Volume

0mL

5mL

5mL

0g/mL

1.006g/mL

1.0392g/mL

V1: 33.5Ml V2: 38.5Ml =5mL 1.0426 g/mL

Density of Beaker 2

CH 204 – Introduction to Chemical Practice Experiment #1– Determination of Densities Cailey Montgomery Hunter Mitchell TA: Atreya Dey January 31st, 2018

Table 3:Class Wide Data: Coke

CH 204 – Introduction to Chemical Practice Experiment #1– Determination of Densities Cailey Montgomery Hunter Mitchell TA: Atreya Dey January 31st, 2018

Table 4: Class Wide Data: Diet Coke

References 1. Coke Density, chemed.chem.purdue.edu/demos/main_pages/1.4.html. 2. 36.34 -- Diet vs. regular Coke®,

web.physics.ucsb.edu/~lecturedemonstrations/Composer/Pages/36.34.html....