Experiment 301

C. SummaryIn Experiment 301, the length of the aluminum metal tube was

measured. The tube was then properly fitted on the expansion base. The initial temperature of the tube (room temperature) was determined by obtaining the resistance of the thermistor using a digital multi-tester. The dial gauge was set to its initial reading. A little amount of water was heated using the steam generator in order for linear expansion to take place. The reading of the dial gauge was recorded at this instance. The resistance of the tube during its hot phase was acquired through the digital multi-tester, producing the respective temperature of the metal tube. The same procedures also apply to the copper metal tube.

The main objective of the experiment is to compute for the coefficient of linear expansion (α). α is the ratio of the change in length to the original length for every degree change in temperature. By carrying out the experiment, four different values were obtained. These are the initial length (Lo), increase in length (∆L), which is obtained from converting the measured divisions from the dial gauge to mm, initial temperature (t rm) and the final temperature (thot). The change in temperature is denoted by ∆t which is calculated by subtracting the initial temperature to the final

temperature. By plugging the values of ∆L, Lo and ∆t in the equation ¿∆ LLo∆ t

,

the experimental value of the coefficient of linear expansion is obtained.Elaborating further, linear expansion is a type of thermal expansion.

Thermal expansion has three types: linear, area and volume. In the experiment, the linear type is solely considered. By critical observations, temperature and thermal expansion go along with each other. These two are dependent quantities. Whenever temperature is increased, expansion takes place – similar to what occurred in the two metal tubes. As steam was generated, they both produced an increase in length. It causes a transformation in the dimensions of a certain material. This is the most significant concept of Experiment 301.

D. Guide Questions

1. Having an incorrect reading of the resistance in the digital multi-tester would produce a wrong value of the initial and final temperatures. Also, acquiring inaccurate values for the increase in length through the use of the dial gauge will produce erroneous results. In order to minimize these errors, there must be keen observation in anything that happens through the course of the experiment.

2. The result will not vary. The aluminum and copper metal tubes will still be heated by the condensed water even if it is not drained. In this manner, the resistance readings of the digital multi-tester will almost be the same.

3. Let x=aluminum and y=copper. Since, x=2(a) and y=3(a), the two metals would have the following coefficients of linear expansion:

E. Analysis

1. Having an incorrect reading of the resistance in the digital multi-tester would produce a wrong value of the initial and final temperatures. Also, acquiring inaccurate values for the increase in length through the use of the dial gauge will produce erroneous results. In order to minimize these errors, there must be keen observation in anything that happens through the course of the experiment.

2. The result will not vary. The aluminum and copper metal tubes will still be heated by the condensed water even if it is not drained. In this manner, the resistance readings of the digital multi-tester will almost be the same.

3. In performing the experiment, the temperature mainly affects the increase in length of the material. As the temperature increases, the extent at which the material expands is reached. They are directly proportional to each other.

F. Conclusion

Assessing the results of the experiment, I therefore conclude that as

temperature rises, expansion is most likely to occur. Materials that are

subjected to changes in temperature will undergo changes in its

dimensions. Additionally, the amount of expansion of a material relies on

the value of its coefficient of linear expansion. The higher its coefficient of

linear expansion, the more it will expand.

Linear expansion is a type of thermal expansion. Thermal expansion is mainly concerned about temperature and the changes in dimension of a material. Looking at the bigger picture, thermal expansion is quantified in Thermodynamics. Being a Chemical Engineering student, Thermodynamics is of great importance. Thermodynamics is centered in studying heat and it is essential for the occurrence of various chemical reactions. Heat is found in almost every part of Chemistry. It is a vital part of what Chemical Engineering is all about.