Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Flame Test Lab Worksheet Activity with Answers Key, Exercises of Chemistry

Flame test Lab is part of general chemistry by Dr. Richard Gilbert at University of South Florida. Flame Test lab with answers

Typology: Exercises

2020/2021

Uploaded on 04/20/2021

ekaraj
ekaraj 🇺🇸

4.6

(29)

264 documents

1 / 2

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
Name:____________KEY__________________Date:_____________________Period:_____
Background
The heat from a laboratory burner will cause the ions of some elements to give off light.
Electrons will absorb the heat energy from the flame and will “jump” to a higher energy level.
When the electrons return to their original energy levels, this absorbed energy is released as
light. Different elements absorb and release different amounts of energy and thus produce
different kinds of light. This light may be visible or invisible, infrared or ultraviolet radiation.
Analysis of this light can be used to identify elements and molecules. In today’s lab, we will
observe the visible range of light emission.
Objectives
1. Perform a flame test to identify the characteristic color of metal ions.
2. Identify the metal ion in an unknown solution.
3. Calculate the energy of emitted photons.
Materials: (per lab group)
10 ml dilute solutions of the following:
Barium Chloride
Calcium Chloride
Lithium Chloride
Potassium Chloride
Sodium Chloride
Strontium Chloride
Unknown Solution
7 Wood Splints
1 Bunsen Burner
Safety Goggles & Aprons
Procedure
1. Put on your safety goggles and an apron.
2. Obtain a wood splint and the barium chloride solution.
3. Dip the wood splint into the solution and allow it to soak for 1-2 minutes.
4. Light Bunsen Burner. USE CAUTION!
5. Remove the splint from the solution and hold the end of the splint into the flame. Do
not burn the splint.
6. Observe and record the color of the flame.
7. Repeat steps 2-6 using the remaining chloride solutions.
8. Obtain an unknown solution from your teacher. Record the number of your unknown.
9. Soak a wood splint in the unknown solution.
10. Hold the splint in the flame and record the color of the flame that is produced.
11. Using your data, identify the metal ion in your unknown solution.
Flame Test Lab
Activity Key
Note:
If chloride compounds are not available, metal nitrate
compounds may be substituted.
Use dilute or approximately 0.1 M solutions
Unknowns:
Number the beakers 1-12.
Add solutions as follows:
1. Strontium Chloride 7. Calcium Chloride
2. Calcium Chloride 8. Strontium Chloride
3. Potassium Chloride 9. Barium Chloride
4. Barium Chloride 10. Potassium Chloride
5. Lithium Chloride 11. Sodium Chloride
6. Sodium Chloride 12. Lithium Chloride
pf2

Partial preview of the text

Download Flame Test Lab Worksheet Activity with Answers Key and more Exercises Chemistry in PDF only on Docsity!

Name:____________KEY__________________Date:_____________________Period:_____

Background The heat from a laboratory burner will cause the ions of some elements to give off light. Electrons will absorb the heat energy from the flame and will “jump” to a higher energy level. When the electrons return to their original energy levels, this absorbed energy is released as light. Different elements absorb and release different amounts of energy and thus produce different kinds of light. This light may be visible or invisible, infrared or ultraviolet radiation. Analysis of this light can be used to identify elements and molecules. In today’s lab, we will observe the visible range of light emission.

Objectives

  1. Perform a flame test to identify the characteristic color of metal ions.
  2. Identify the metal ion in an unknown solution.
  3. Calculate the energy of emitted photons.

Materials: (per lab group) 10 ml dilute solutions of the following: Barium Chloride Calcium Chloride Lithium Chloride Potassium Chloride Sodium Chloride Strontium Chloride Unknown Solution 7 Wood Splints 1 Bunsen Burner Safety Goggles & Aprons

Procedure

  1. Put on your safety goggles and an apron.
  2. Obtain a wood splint and the barium chloride solution.
  3. Dip the wood splint into the solution and allow it to soak for 1-2 minutes.
  4. Light Bunsen Burner. USE CAUTION!
  5. Remove the splint from the solution and hold the end of the splint into the flame. Do not burn the splint.
  6. Observe and record the color of the flame.
  7. Repeat steps 2-6 using the remaining chloride solutions.
  8. Obtain an unknown solution from your teacher. Record the number of your unknown.
  9. Soak a wood splint in the unknown solution.
  10. Hold the splint in the flame and record the color of the flame that is produced.
  11. Using your data, identify the metal ion in your unknown solution.

Flame Test Lab

Activity Key

Note: If chloride compounds are not available, metal nitrate compounds may be substituted.

Use dilute or approximately 0.1 M solutions

Unknowns: Number the beakers 1-12. Add solutions as follows:

  1. Strontium Chloride 7. Calcium Chloride
  2. Calcium Chloride 8. Strontium Chloride
  3. Potassium Chloride 9. Barium Chloride
  4. Barium Chloride 10. Potassium Chloride
  5. Lithium Chloride 11. Sodium Chloride
  6. Sodium Chloride 12. Lithium Chloride

Name:____________KEY__________________Date:_____________________Period:_____

Data Table

Metal Ion Flame Color Produced

Metal Ion Flame Color Produced Barium Green Potassium Lavender

Calcium Orange Sodium Yellow

Lithium Red Strontium Red

Unknown Number Flame Test Color Identity of Unknown 1, 8 Red Strontium 2, 7 Orange Calcium 3, 10 Lavender Potassium 4, 9 Green Barium 5, 12 Red Lithium 6, 11 Yellow Sodium

Questions

  1. Fireworks are made by combining metals with explosive materials. Using your data, which metal(s) do you predict would be used in the production of green fireworks? Barium Note: Sometimes sodium is added to barium to produce greenish-yellow fireworks
  2. A flame test performed on an unknown element emits a photon of light with a wavelength of 459 nm. What is the energy content, in joules, of this photon?

-34 8

6.33 x 10 J s 3.00 x 10 m s

= = 4.33 x 10 J

4.59 x 10 m

= 4.33 x 10 J

E

E

  1. Emission spectrums are produced from the release of light by electrons in varying energy levels. The following is an emission spectrum of hydrogen gas. Calculate the frequency of each wavelength emitted.

8 -1 - x

14 14 14 14 1 2 3 4

3.00 x 10 m s

= = s s = Hz

= 7.32 x 10 Hz ; f = 6.91 x 10 Hz ; f = 6.17 x 10 Hz ; f = 4.57 x 10 Hz

x x

f f

f

λ 1 = 410 nm λ 2 = 434 nm λ 3 = 486 nm λ 4 = 657 nm