DE LA SALLE UNIVERSITY - DASMARIÑAS College of Science PHYSICAL SCIENCES DEPARTMENT Dasmariñas City, Cavite

Determination of Densities

Group 3 - ECE 12Paul Anthony S. Dela Cruz

Gwenn G. Dela VictoriaChristian Dane A. Esteva Nicolo Martin M. Eugenio

Neil Aaron M. Gayetta

ABSTRACT

On this experiment the group would find the changes of chemical properties in metal, due to the metal being attracted into different reagents, through the analysis of their flame colors. First the materials needed on this experiment are Nichrome wire (nickel-chromium wire), Alcohol lamp, Watch glass, medicine dropper, Stirring rod, Porcelain spatula, and lastly the reagents. By doing this experiment, the main procedure of it will attract the reagents on the metal of the Nichrome wire. By first cleansing the wire with concentrated hydrochloric acid (HCl) then heating it using the alcohol lamp it remove the impurities. Next by placing the Nichrome wire in the blue section of the flame the group could observe the change of the flame color of the metal. On the first reagent “CaCl2” the metal, Nichrome wire, reacted to the solution forming an orange colored flame. Then on the 2nd reagent “CuCl2” the metal reacted to the solution forming a green flame. On the 3rd reagent “NaCl” the metal reacted to the solution forming a yellow flame. On the 4th reagent “LiCl” it formed a red flame. And the final reagent “KCl” formed a violet flame. Lastly the group calculated for the v(HZ) and (nm); the (nm) of the reagents are: CaCl2 (600), CuCl2 (525), NaCl (570), LiCl (710), and lastly KCl (415). For v(HZ) the of the following reagents: CaCl2 had 5x1014, for CuCl2 it had 5.72x1014, for NaCl it had 5.26x1014, for LiCl it had 4.22x1014, and lastly for KCl it had 7.22x1014.

INTRODUCTION

An atom is the smallest component of an element having the chemical properties of the element. It consists of a nucleus which contains combinations of neutrons and protons. One or more electrons bound to the nucleus of protons determines the identity of the element. When an atom absorbs energy from a flame or electric discharge, it absorbs just enough energy to excite its electrons from a lower energy state to a higher energy state. Alternatively, when the atom from an excited state returns to a lower energy state, it emits the energy previously absorbed in the form of light. In this experiment the main goal is to determine what color the flame emitted when attracted to a reagent.(2)

MATERIALS AND METHODS

First, the nichrome wire was dipped in about 5-7ml of concentrated hydrochloric acid. Then we heated it in the hottest region in the flame until there was no visible color. We then dipped the wire into a CaCl2 Solution containing 3-4 drops of water. The solution was then contained in a watch glass. Then the wire was then heated to the hottest region of the flame. The flame color was then observed and recorded. The wire was then sterilized using the cleaning process. After which the same process was done with the following salt solutions: CuCl2, NaCl, LiCl, and KCl.(1)

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RESULTS AND DISCUSSIONS

After calculating the energy emitted, or light is equal to the energy difference between the two energy states and is inversely proportional to its wavelength, the equation and outline are seen in the table 2.0. The wavelength of different salt solutions and the frequency of light are: CaCl2 is 600- 5x1014 , CuCl2 is 525 - 5.72x1014, NaCl is 570- 5.16x1014, LiCl 710 - 4.22x1014and KCl 415 - 7.22x1014. This energy corresponds to particular wavelengths of light, and so produces particular colors of light.(3)

5 compounds were observed: CaCl2,CuCl2,NaCl,LiCl,KCl

The orange, yellow, and red colors in a flame do not relate to color temperature alone. Gas excitations also plays a major role in flame color. One of the major constituents in a burning flame, soot, has a complex and diverse composition of carbon compounds. The variety of these compounds creates a practically continuous range of possible quantum states to which electrons can be excited. The color of light emitted depends on the energy emitted by each electron returning to its original state.(4)

Within the flame, regions of particles with similar energy transitions will create a seemingly continuous band of color. For example, the red region of the flame contains a high proportion of particles with a difference in quantum state energies that corresponds to the red range of the visible light spectrum.(5)

REFERENCES

(1) Figueroa, L. and Samonte.J. Laboratory Manual in General Chemistry. 3rd Edition. 2010. C&E Publishing. Philippines.

(2) General Chemistry Online “The Quantum theory” from http://antoine.frostburg.edu/chem/senese/101/quantum/

(3) AUS-e-TUTE. “Flame Test”. Chemistry from http://www.ausetute.com.au/flametest.html

(4) Causes of Color “What causes colors in flames?” from http://www.webexhibits.org/causesofcolor/3BA.html

(5) Kent Chemistry “Wavelength (l), Frequency (n) and Energy Calculations (E)” 2015-2016from http://www.kentchemistry.com/links/AtomicStructure/waveequations.htm

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Prepared by:

Salt Solution Flame Color λ (nm) v(Hz) E(J)

CaCl2 Orange 600 5 x 1014 3.315 x 10-19

CuCl2 Green 525 5.72 x 1014 3.79 x 10-19

NaCl Yellow 570 5.16 x 1014 3.49 x 10-19

LiCl Red 710 4.22 x 1014 2.80 x 10-19

KCl Violet 415 7.22 x 1014 4.79 x 10-19

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Paul Anthony S. Dela Cruz Gwenn G. Dela Victoria

Abstract Results and Discussion and AbstractBS Electronics Engineering BS Electronics Engineering

Christian Dane A. Esteva Nicolo Martin M. EugenioIntroduction Materials and MethodsBS Electronics Engineering BS Electronics Engineering

Neil Aaron M. GayettaResults and Discussion

Editor- In - ChiefBS Electronics Engineering

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