Metal Ion Flame Tests - CORE PRACTICAL Flashcards
When burnt, potassium ions will cause the flame to become which colour?
Lilac
When burnt, lithium ions will cause the flame to become which colour?
Crimson
When burnt, calcium ions will cause the flame to become which colour?
Orange-red
When burnt, sodium ions will cause the flame to become which colour?
Yellow
When burnt, copper ions will cause the flame to become which colour?
Blue-green
The burning of which metal ion results in a lilac flame?
Potassium (K+)
The burning of which metal ion results in a crimson flame?
Lithium (Li+)
The burning of which metal ion results in an orange-red flame?
Calcium (Ca 2+)
The burning of which metal ion results in a yellow flame?
Sodium (Na+)
The burning of which metal ion results in a blue-green flame?
Copper (Cu 2+)
State a problem for interpreting the result of a flame test if the sample used consists of multiple different ions
Flame colours of some may be masked possibly leading to incorrect interpretations
What are flame tests used for?
Identifying the metal ions in an ionic compound
The wire loop used to hold an ionic compound sample in the flame for a metal ion flame test should be made of which alloy?
Nichrome
Because of its high melting point and that non of its constituents lend any colour to the flame
To clean it, the nichrome wire loop should be submerged in what at the start of the practical?
Dilute Hydrochloric acid (HCl)
Give two pieces of equipment required for a metal ion flame test practical
Bunsen Burner
Nichrome wire loop
What is a nichrome wire loop used for in a metal ion flame test?
Holding an ionic compound sample in the blue bunsen flame
Describe in 4 steps the process of conducting a metal ion flame test
1) Submerge a nichrome wire loop in dilute HCl to clean it
2) Place cleaned loop in the ionic compound sample you wish to test
3) Hold loop with sample on in a blue bunsen burner flame
4) Observe and record any colour change to the Bunsen’s flame
Why should the nichrome wire loop be first submerged in dilute HCl?
To clean it, ensuring more accurate results by the removal of the residue of other compounds which could otherwise interfere with or obscure the colour change caused by the new ionic compound