Flame Tests Objective: to explore and discover energy concepts associated with flame colors generated from different cations
Data to collect: • Cation Color Barium Calcium Copper Strontium Lithium *Sodium *Potassium *Sodium + Potassium Also starred cations with cobalt glass
And now . . . The moment you’ve all been waiting for . . . • Obtain an unknown sample from instructor and determine which cation it is. If you struggle, AT LEAST determine which cations it ISN’T. Write “unknown letter/number” on your data table and color.
Conclusion Questions • What metal cation do you predict is in your unknown (include letter/number of unknown)? • Would this method of ID be practical to determine metals in a mixture? Why/why not? • Which cation color remained more consistent through cobalt glass, K+ or Na+? Explain why this is. • How did the NO3- ion affect the colors emitted by the samples? • Why might “Flame Tests” sometimes be invalid? • How else might you identify metals besides using flame tests?
Summary • Following the usual summary format, discuss how flame tests relate to energy and how they can be used to identify metal cations. Use the emission spectrum portion of your text as a reference to explain the relationship between flame color and the element’s “energy”.