2nd 6wk Flame Test template

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Your Name, Your Class Period (2 pts)

Flame Test Lab

Introduction: In this lab you will observe the colors produced when compounds are introduced into a flame and the electrons become excited. You will use your observations to estimate the wavelength of light produced, then calculate the frequency and energy of the light.

Pre-lab:

Complete the following table: Highlight the word “color” in the corresponding color in the COLOR column. (13 pts)

Color

Red

Wavelength

7.5x10

-7 m - 6.2x10

-7 m

COLOR

color

6.2 x10

-7 m - 5.9 x10

-7 m color Orange

Yellow

Green

5.9 x10

5.7 x10

-7

-7 m - 5.7 x10 m - 5.2 x10

-7

-7 m m color color

Blue

Indigo (dark blue)

Violet

5.2 x10

5.0 x10

4.4 x10

-7

-7

-7 m - 5.0 x10 m - 4.4 x10 m - 3.8 x10

-7

-7

-7 m m m color color color

Background Info:

For this experiment, it is important to understand that the wavelength and the frequency of the colors you are seeing are related in the following manner: c = λf c = speed of light (of any color) = 3.0×10

8 m/s

λ = wavelength f = frequency

As you read the wavelength of each of the colors of light, you can then determine the frequency of that color of light. Once you know the frequency, you are then able to determine the amount of energy that a photon of a particular color of light possesses by using the following formula:

E = hf

E= energy

h = Planck’s constant = 6.63×10

-34

J∙s f = frequency

Purpose: To observe the colors produced when compounds are introduced into a flame and the electrons become excited. To estimate the wavelength of light produced, then calculate the frequency and energy of the light.

Your Name, Your Class Period (2 pts)

Safety: Both barium chloride and cupric chloride are toxic by inhalation and ingestion. Use tiny amounts and

WASH HANDS when leaving the lab. Do not rub eyes or face without washing hands first.

Chemical Inventory

Chemical

Lithium Chloride

Potassium Chloride

Calcium Chloride

Copper (II) chloride

Hazards

Moderately toxic by ingestion.

Slightly toxic by ingestion.

Slightly toxic.

HIGHLY toxic by ingestion and inhalation. Use extreme caution.

Procedure

1.

At each station, wooden splints have been soaking in a solution of dissolved metal salt. Choose one splint, and hold the wet end of the splint in the burner flame and observe the first color you see.

** When the wooden splint begins to dry out and you see an orange flame where there was not one before, this indicates the splint is burning, not the metal ions. We don’t care about that color.

2.

3.

Only use 1 wooden splint per station! Please be considerate of classes coming after you.

Place the used (burnt) splint in the waste beaker specified by your teacher.

Use your chart from your pre-lab to estimate the wavelength of the color being produced.

Data and Observations (17 pts):

Formula Estimated Wavelength (m)

Chemical Color Produced

(on beaker) Look at your pre-lab!

Lithium Chloride

Potassium Chloride

Calcium Chloride

Strontium Chloride

Copper (II) Chloride

Unknown N/A

Your Name, Your Class Period (2 pts)

Calculations & Analysis: For each chemical, do the following calculations.

1.

2.

Using the estimated wavelength, calculate the frequency of the light produced.

Using the frequency of the light, calculate the energy of each photon of light produced.

On the provided sheet, show one example of a frequency calculation and one example of an energy calculation. (20 pts)

Enter your calculated frequencies and energies in the table below. REMEMBER YOUR UNITS (15 pts):

Chemical

Lithium Chloride

Frequency Energy

Potassium Chloride

Calcium Chloride

Strontium Chloride

Copper (II) Chloride

Unknown

Analysis: Relating electrons to light- fill in the blanks! Highlight your answers in yellow (13 pts)

1.

Electrons occupy ________________.

2.

An electron in its lowest energy level is in its ____________ state.

3.

To jump from their ground state to a higher energy level known as the “excited state”, electrons need to

__________ ____________.

4.

When electrons _______________ ________________ somehow, they can then occupy a HIGHER

ENERGY LEVEL. They jump up to the next level and are said to be in their “____________

_______________”.

5.

When electrons _______________ ______________ they will fall back down to their _____________

______________ and release energy, and some of it is released as waves we can see – _____________!

Your Name, Your Class Period (2 pts)

Conclusion:

A Paragraph of Awesomeness (20 pts total)

1.

2.

3.

Paragraph: must be written as such (2 pt)

Spelling and grammar (3 pt)

Complete sentences. (5 pt)

Write an expository paragraph using complete sentences and your own words. Include the information from each question below. You must correctly use the following ten vocabulary terms in your answers (10 pt):

energy, wavelength, frequency, color, energy level, ground state, excited state, light, ion, electron.

**UNDERLINE THESE

TERMS when they appear in your paragraph!!

1.

What procedure did you follow in this lab to test the different metal ions?

2.

What was your unknown metal ion and how do you know?

3.

What happens to the electrons in metal ions when they are heated in a flame?

4.

After the metal ions are heated, why is colored light released? Explain in terms of the movement of electrons and location of energy levels.

5.

Discuss why different metal ions produce different colors in a flame test.

WRITE YOUR PARAGRAPH BELOW USING COMPLETE SENTENCES, ANSWERING ALL 5

QUESTIONS, AND INCLUDING ALL VOCABULARY TERMS.

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