Bunsen Burner Study Guide

Name the different parts of the Bunsen Burner

1. Inner cone (hottest part of flame)

2. Barrel

3. Oxygen inlet

4. Gas inlet

5. Flame adjuster

6. Base

Bohr Theory

electrons occupy only specific energy levels

• when an atom absorbs sufficient energy, an electron can “jump” to a higher energy level

  • higher energy levels = less stable

• if a lower energy level is available the electron will “fall” back

• (400 to 700 nm = visible light)

  • (White light is a continuous spectrum)

• The color of the light depends on specific energy change taking place

The lab

The emission of energy in the visible portion of the spectrum as those electrons return to lower energy levels produces a colored flame

Order of lab

1. Clear off the desk of papers

2. Get goggles or safety glasses

3. Get beaker and fill halfway with water for used matches

4. Get Bunsen burner

5. Get matches

When lighting a Bunsen burner, which do you do first?

- Light the match

Where should the person who is turning on the gas jet stand?

- Behind the sink

Which direction of the handle means the gas is on?

- Parallel to the jet

Observations in Lab

• Ba⁺²: yellow-orange

• Cu⁺²: Green/Cyan

• Sr⁺²: Red

• Li⁺¹: Pink-red

• K⁺¹: Link Pink/Peach

• Na⁺¹: Dark orange

• Ca⁺²: Orange

What does a flame test indicate about the energy changes taking place among the electrons in a metallic ion?

Heat metallic ions w/ flame excites electrons. Electrons then comes back to “rest” - energy released in form of visible light

List the colors of visible light from shortest to longest wavelengths. Which color has the highest energy? Which color has the lowest frequency?

Violet (shortest, highest E), indigo, blue, green, yellow, orange, red (longest, lowest E)

How do you think metallic salts are used in fireworks?

Creates different colors

When heating milk on a gas stove, some milk splashes out and the flame turns orange. Explain why this occurs.

Milk contains calcium which, when burned in a flame it turns orange