Chemistry Lab 1 4U

Purpose:
The purpose of this experiment is to observe the colours produced when the solutions of metal ions are heated to high temperatures, then to explain the results in terms of the energy levels of the metal ions. Lastly, to use the flame colours to identify a series of unknowns.
Hypothesis:
Substance being tested
Predicted flame colour
NaCl(s)
Yellow
NaCl
Red-Orange
NaNO3
Dark Orange
LiNO3
Red
Sr(NO3)2
Dark Red
KNO3
Blue-Indigo
Ba(NO3)2
Yellow-Green
Cu(NO3)2
Green
Ca(NO3)2
Red-Orange
Ni(NO3)2
Yellow-Green

Materials:
Nichrome test wire Bunsen Burner 150 mm test tubes (14) 6.0 mol/L HCl Solid NaCl 0.50 mol/L NaCl 0.50 mol/L NaNO3 0.50 mol/L LiNO3 0.50 mol/L Sr(NO3)2 0.50 mol/L KNO3 0.50 mol/L Ba(NO3)2 0.50 mol/L Cu(NO3)2 0.50 mol/L Ca(NO3)2 0.50 mol/L Ni(NO3)2 50 mL beaker Bunsen Burner lighter
Procedure:
See handout Flame Colours of Metal Ions
Observations:
Substance being tested
Appearance
Flame colour
Solid NaCl
White, grainy
Orange
NaCl
Colourless solution
Bright Orange
NaNO3
Colourless solution
Dark Orange
LiNO3
Colourless solution
Red-Orange
Sr(NO3)2
Colourless solution
Dark Red
KNO3
Colourless solution
Light Purple
Ba(NO3)2
Colourless solution
Yellow-Green
Cu(NO3)2
Transparent, blue
Green
Ca(NO3)2
Colourless solution
Red-Orange
Ni(NO3)2
Transparent, blue
Green-Blue
Unknown A
Colourless solution
Green
Unknown B
Colourless solution
Light Purple
Unknown C
Colourless solution
Bright Orange
Unknown D
Colourless solution
Dark Red

Questions:
1. Unknown A  Ba(NO3)2 Unknown B  KNO3 Unknown C NaCl (aq) Unknown D  Sr(No3)2
2. The ranking would be as follows: Sr(NO3)2 , LiNO3, Ca(NO3)2, NaNO3, Solid NaCl, NaCl, Ba(NO3)2, Cu(NO3)2, Ni(NO3)2 and lastly KNO3.

3. Most of the anions are nitrate in this experiment because nitrate doesn’t emit colours that interfere with the colours metal ions are emitting. That