AP Chemistry students conduct the “flame test”

Senior Stephanie Tian cheerfully grins at the sight of  a fluorescent green flame.

Senior Stephanie Tian cheerfully grins at the sight of a fluorescent green flame.

LAMBERT HIGH SCHOOL – Students from Dr. Young’s first and third period AP Chemistry classes observed the emission spectra from selected cations, or positively charged ions, on Thursday, September 8th.

Students – working in groups of four – were instructed to conduct the “flame test”: a test where a small amount of a substance is heated and as a result, a characteristic color of the flame is observed. Within the lab sheet given, directions stated to carry out the test and observe and record the color of emitted light from several aqueous metallic salt solutions.

Platinum rods were used to transfer the metal solutions from a glass sample dish to the low-kept flame of the bunsen burner. When switching between metallic samples, students were directed to sterilize the rods by dipping them into alcohol and placing them into the flames.

When placed in contact with the flame, Potassium (K) produced a pinkish violet color, Copper (Cu) produced a greenish-blue color, Lead (Pb) produced a red color, Calcium (Ca) produced a reddish-orange color, Sodium (Na) produced a orange color, and Barium (Ba) produced a yellowish-green color.

Once finished testing the specified solutions, students were asked to additionally test three unknown metals and observe and document the respective colors emitted when touching the flame. Unknown metals labeled #1 and #2 emitted a bright orange color, while unknown metal #3 emitted a reddish-orange color.

Later, students were told that unknown metal #1 was a combination of Copper (Cu) and Sodium (Na), unknown metal #2 was a combination of Lithium (Li) and Sodium (Na), and unknown metal #3 was a combination of Calcium (Ca) and Lithium (Li).

Following the completion of the lab, each group of students properly cleaned and sanitized the lab table.After the lab was fully closed, students took time to answer various analysis questions and to write a concluding lab statement.

When asking various students about their opinions on the lab, the overall feedback was conclusively positive. Not only did the lab provide students with great knowledge, but it also gave students an opportunity to relax and just have fun in the science room.