Experiment Date Title Purpose: Shanique Thomas

Shanique Thomas
Experiment: 2
Date: October 12, 2014
Title: Flame Test
Purpose: To experiment with flame tests on different salts and to predict the identity of unknown
metal ions from the tests.
Introduction: The flame test is used to visually determine the identity of an unknown metal ion
based on the characteristic color the salt turns the flame of a Bunsen burner. The heat of the
flame excites the electrons of the metals ions, causing them to emit visible light. Every element
has a signature emission spectrum that can be used to differentiate between one element and
another. In this experiment the flame colors of different metals will be observed and recorded
and unknown ions identified using such test.
Apparatus and Materials: Bunsen burner, 10 individual vials of solution, Nichrome wire, Nitric
acid, 2 unknown solutions
Procedure:
1. Appropriate vials of unknown solutions were collected
2. A nichrome wire was cleaned by first dipping it into nitric acid and holding it in the
colorless flame of the Bunsen burner. This was repeated until the wire imparted no color
to the flame
3. For each solution of known ions, the color of the flame just above the wire was observed.
Only the tip of the wire was heated. The wire was cleaned thoroughly after each test and
the color of the flame for each metal compound was recorded in a data table.
4. The unknown solutions were then tested in the same manner as the known solutions
were. The answers were also placed in the data table.
Safety considerations:
1. To prevent cross contamination, the nichrome wire used in each solution was placed
immediately beside each vial of solution so that it can be reused.
2. Contact with skin and eyes were avoided when handling the nitric acid as it is caustic and
corrosive. Safely precautions were exercised.
Data Table:
Shanique Thomas
A table showing the Observations for each solution
Salt Solution
Symbol
Observation
Lead
Pb2+
Very light blue flame
Calcium
Ca2+
Bright orange-red flame
Magnesium
Mg2+
No visible flame color was seen
Barium
Ba2+
Yellow/ pale green flame
Zinc
Zn2+
Bluish green fame
Aluminum
Al3+
Colorless flame produced. Orange sparks

were seen
Sodium
Na+
strong persistent orange flame
Potassium
K+
Pink flame with purple sparks
Iron (||)
Fe2+
Intense yellow flame
Iron (|||)
Fe3+
Orange-red flame
Manganese
Mn2+
Yellow sparks produced. Green flame was

seen
Copper
Cu2+
Blue green flame
Unknown A
K+
Bright pink-red flame
Unknown B
Mn2+
Intense yellow-green flame
Of known
and
unknown
ions
Shanique Thomas
Discussion:
In performing such an experiment, several inaccuracies could have occurred when using the
flame test to identify ions. For instance, Impurities or contaminants may affect the test results
causing inaccuracies. Another is that the test cannot differentiate between all elements. Several
metals produce the same flame color. Some compounds do not change the color of the flame at
all. For the purpose of this experiment however, only the color of the flames were being
observed for known metals and also used to identify unknown ions.
Many elements produce colors in the flame when heated. The origin of this phenomenon lies in
the configuration of the electrons in the atoms of the different elements. One or more electrons
in an atom may absorb energy in sufficient amounts to jump to an orbit farther away from the
nucleus. When this happens, the electron is said to be in a higher energy level. When the electron
has been promoted to a higher energy level, the atom is said to be in an excited state.
When the electrons are in their lowest energy orbits (closest to the nucleus), the atom is said to
be in its ground state. When the electrons drop from a higher energy level to a lower energy level
(in an orbit closer to the nucleus), energy is released. This energy being released is what enables
us to exercise the flame test as a suitable method for detecting metals. The energy which was
supplied was the heat energy from the Bunsen burner which caused the electron in that particular
element to a lower energy level. The color of light emitted depends on the energy emitted by
each electron returning to its original state. The unknown samples A and B were identified by
using the color of light emitted and comparing it to the standard colors emitted from different
metal elements to detect a possible identity of the element.
Conclusion:
Using the flame test, the sample of unknown metals was identified by the different colors they
emitted.
Unknown sample A was found to be Potassium (K+)
Unknown sample B was found to be Manganese (Mn2+)
Shanique Thomas

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Shanique Thomas

A table showing the Observations for each solution

Very light blue flame

Bright orange-red flame

No visible flame color was seen

Yellow/ pale green flame

Bluish green fame

Colorless flame produced. Orange sparks

strong persistent orange flame

Pink flame with purple sparks

Intense yellow flame

Yellow sparks produced. Green flame was

Blue green flame

Bright pink-red flame

Intense yellow-green flame

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