Worksheet: Tests for Transition Metals
In this worksheet, we will practice identifying transition metal complexes based on their flame tests and interactions with sodium hydroxide and ammonia.
Q1:
When dissolved in water, the chloride of a first-row transition metal reacts with dilute ammonia to form a pale green solid and with concentrated ammonia to form a blue solution. What is the identity of the element ?
- A
- B
- C
- D
- E
Q2:
When dissolved in water, which of the following transition metal chlorides does not react with sodium carbonate to produce a blue or green precipitate?
- A
- B
- C
- D
- E
Q3:
When a reagent is added to a strongly basic solution of chromium(III) nitrate, a yellow solution is produced.
What color is the original solution?
- AYellow
- BGreen
- CPink
- DOrange
- EViolet
Which species produces the yellow color of the final solution?
- A
- B
- C
- D
- E
Which of the following is a possible molecular formula for the reagent ?
- A
- B
- C
- D
- E
What is the oxidation state of chromium in the final yellow solution?
- A+4
- B+2
- C+6
- D+3
- E+7
Q4:
At pH 3, a dilute aqueous solution of iron(III) chloride is yellow in color.
Which species is mostly responsible for the color of this solution?
- A
- B
- C
- D
- E
What change is observed if concentrated acid is added to this solution?
- AA green solution is produced.
- BA green solid precipitates.
- CA lilac solid precipitates.
- DAn orange solid precipitates.
- EA lilac solution is produced.
If added to this solution, which of the following reagents would not react to form a solid material?
- ASodium hydroxide
- BAmmonia
- CSodium thiocyanate
- DSodium sulfate
- ESodium carbonate
As the pH of the solution increases, what happens to the geometry of the transition metal complex and the frequency of the light absorbed?
- AThe complex changes from octahedral to tetrahedral and lower-frequency light is absorbed.
- BThe geometry of the complex is unchanged and lower-frequency light is absorbed.
- CThe geometry of the complex is unchanged and higher-frequency light is absorbed.
- DThe complex changes from tetrahedral to octahedral and lower-frequency light is absorbed.
- EThe complex changes from octahedral to tetrahedral and higher-frequency light is absorbed.
Q5:
When a complex of vanadium reacts with zinc under acidic aqueous conditions, the color of the solution changes from blue to purple.
What is the structure of the original complex?
- A
- B
- C
- D
- E
What is the oxidation state of vanadium in the final complex?
- A+5
- B+3
- C+6
- D+4
- E+2
If the original vanadium complex is instead oxidized, what is the color of the resulting solution?
- AYellow
- BGreen
- CPurple
- DBlue
- EColorless
Q6:
Many cobalt(II) salts dissolve in water to produce the colored complex ion . Adding dilute ammonia to this solution produces a colored precipitate, which redissolves in the presence of excess ammonia.
What color is an aqueous solution of the ion?
- AYellow
- BBlue
- CPink
- DGreen
- ERed
Draw an energy level diagram illustrating the arrangement of valence d electrons in the ion.
- A
- B
- C
- D
- E
What is the formula of the major solid product when aqueous ions react with dilute ammonia?
- A
- B
- C
- D
- E
When excess ammonia is added to aqueous ions, the resulting complex ion has a 2+ charge. How does this reaction affect the geometry of the complex ions and the frequency of the light it absorbs?
- AThe complex converts from octahedral to tetrahedral and lower-frequency light is absorbed.
- BThe complex converts from tetrahedral to octahedral and lower-frequency light is absorbed.
- CThe complex converts from octahedral to tetrahedral and higher-frequency light is absorbed.
- DThe geometry of the complex is unchanged and higher-frequency light is absorbed.
- EThe geometry of the complex is unchanged and lower-frequency light is absorbed.