Get Lab:flame Tests

The purpose is to observe the characteristic colors produced by certain metallic ions when vaporized in a flame and then to identify an unknown metallic ion by means of its flame test.

The flame test is used to visually determine the identity of an unknown metal or metalloid ion based on the characteristic color the salt turns the flame of a bunsen burner. The heat of the flame converts the metal ions into atoms which become excited and emit visible light.

Because each element has an exactly defined line emission spectrum, scientists are able to identify them by the color of flame they produce. For example, copper produces a blue flame, lithium and strontium a red flame, calcium an orange flame, sodium a yellow flame, and barium a green flame.

A flame test is a qualitative analysis used by the chemist to identify the metal and metalloid ion in the sample. Not all metal ions emit colour when heated in the gas burner. A flame test is the simplest way of identifying the presence of group 1 metal ions in the compound.

The colors observed during the flame test result from the excitement of the electrons caused by the increased temperature. The electrons "jump" from their ground state to a higher energy level. As they return to their ground state, they emit visible light.

The test is performed by dipping a wire or wooden splint into a sample solution or coating it with the powdered metal salt. The color of a gas flame is observed as the sample is heated. If a wooden splint is used, it's necessary to wave the sample through the flame to avoid setting the wood on fire.

To carry out a flame test: dip a clean wire loop into a solid sample of the compound being tested. put the loop into the edge of the blue flame from a Bunsen burner....Flame tests. Ion presentFlame test colourSodium, Na +YellowPotassium, K +LilacCalcium, Ca 2+Orange-redBarium, Ba 2+Green2 more rows