About

I made ScienceFix.com to share my favorite demos that I do in my middle school science classes.  

Contact Me
Search ScienceFix.com
Twitter
Delicious
Media that I like...
  • Something Funny Happened on the Way to the Moon
    Something Funny Happened on the Way to the Moon
    by Sara Howard
  • NOVA - Origins
    NOVA - Origins
    starring Neil Degrasse Tyson
  • Human Body: Pushing the Limits
    Human Body: Pushing the Limits
    starring Bray Poor
« Handboiler | Main | Video Demo: Muscle Pair »
Saturday
Jun202009

Video Demo: Flame Tests

Every chemical has its unique characteristic properties. These properties can include hardness, density, melting point, boiling point, color, taste, texture etc. No matter what sample you have of a pure substance they will display its characteristic properties. This is how a an unknown chemical can be identified. The properties of the unknown chemical can be compared to the properties of known chemicals. In this activity there are 3 unknown chemicals (X, Y, and Z) that are to be identified based on 5 properties: color, boiling point, melting point, density, and color when burned. This is a simple and quick lab activity. The handout has the density, boiling point, and melting point filled in already. The students must observe the color and the color when burned–a flame test. Slide 1 shows the materials needed for the activity (the 3 chemicals are copper sulfate, strontium chloride, and lithium chloride). Slide 2 shows the Bunsen burner flame with the typical blue color. Slide 3 shows the inoculating loop collecting some of chemical Y. When the different chemicals are put in the flame, they burn at different colors (Slide 4 shows copper sulfate’s green flame, and slide 5 shows lithium chloride’s red flame).

Tips: Make sure students are careful to not contaminate the tubes and to thoroughly clean loop before testing each chemical.

Safety: Make sure students wear goggles, and know how to properly use a Bunsen burner safely.

BubbleShare: Share photos - Easy Photo Sharing

This is a variation on the flame test lab. Instead of using a Bunsen burner, a denatured alcohol flame is used (the best results is achieved by using methanol). Put a spoonful of strontium chloride into a Pyrex petri dish (this glass can take the heat, any other non Pyrex glass will break). Put about 2-3 spoonfuls of denatured alcohol into the dish. Swirl around to mix. Carefully light the alcohol on fire. You will probably need to swirl it so that the strontium chloride will burn and produce the red flame (lower left image). Try this with other salts and compounds that are safe to burn and will give color (like copper sulfate–lower right image).

ultra flame test materials

ultra flame test red ultra flame test green

 

Precautions: ONLY TEACHER DEMO! Be sure to use only Pyrex petri dish. The dish will get very hot! Don’t let water hit it right away. Be sure to blow flame out.

PrintView Printer Friendly Version

EmailEmail Article to Friend

References (2)

References allow you to track sources for this article, as well as articles that were written in response to this article.
  • Response
    Football is actually one of the greatest sports in America. It has a major following.
  • Response
    Response: dumpsters
    ScienceFix - Science Fix - Video Demo: Flame Tests

Reader Comments

There are no comments for this journal entry. To create a new comment, use the form below.

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
Post:
 
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>