Lab Report

Report A

Tear out the originals from your work above and turn it into your lab instructor. Although no points are assigned to this, students who fail to turn in their notes will have 2 points deducted from their report score out of the In point total.

Report B

For this report, completely answer each of the additional questions. Your instructor will let you know the way in which they want you to submit the report (lab notebook, word processing document, iLearn etc). Pre-lab #1 gives a detailed background on emission of light. Please refer to it when answering some of the questions in the post-lab write-up.

1. Create a table that summarizes the flame test observations for the various substances investigated in Part A. For Part B, list the ingredients used to compose the star made, and the effects seen in the flames.

2. The answers to the questions below will be turned in as your lab report. You do not need to reproduce the questions.

a. What differences did you see in the spectral profile of the different flame tests?

b. Which of the chemicals observed during the flame tests, the nitrate salts or the Fe and Mg metal powders, are a result of continuous emission and which is a result of a line emission? What evidence do you have to support your conclusion?

c. What does the observed color from a black body emittor indicate about the temperature of a metal? You saw different colored light from magnesium than from iron. Which metal powder, Fe or Mg, burns at a higher temperature?

d. You saw a different colored light for Ba(NO3)2, Sr(NO3)2, and NaNO3. Which part of the compound, the metal cation (Ba2+, Sr2+, Nat) or the anion (NO31, do you think is responsible for the color? Explain your reasoning.

e. How do you know that water wasn't responsible for the effect you saw with the nitrate salts?

f. Emergency flares are commonly red. What element do you think the flare contains that gives rise to the red color? What type of emission is responsible for the light seen, line or continuous?

g. Suppose that you go to a 4th of July celebration show and the fireworks. Identify the chemicals responsible for the white and gold sparkles and flashes, and the chemicals responsible for the green, red and gold colors seen in a firework. Explain if the light seen was due to heating the chemical or due to electron transitions taking place in the atoms of the chemical.