Chapter U1.17, Problem 9E

Interpretation Introduction

Interpretation:

The colors of the flame for the given compounds are to be predicted and explained.

Concept introduction:

Different compounds produce different colors in a flame test. Flame test is done by heating a small sample of a compound in a flame such as a Bunsen burner. The color of the flame determines which atom is present in the compound.

Answer to Problem 9E

The following table shows the colors of flame produced by given compounds.

Compounds	Flame color
Na2CO3	Yellow - orange
Ba(OH)2	Green
KOH	Pink - lilac
K2CO3	Pink - lilac
BaO	Green

Explanation of Solution

Given information:

Following compounds are given:

Na2CO3

Ba(OH)2

KOH

K2CO3

BaO

Each metal atom is associated with a specific flame color. A flame test can be used to confirm the presence of a particular atom in a compound. Color patterns with a flame test indicate the presence of a specific metal atom in a compound. Non -metal part of the compound does not give any color.

1. Na₂CO₃ - All sodium compounds burn with yellow - orange flame. Sodium carbonate is also a sodium compound. So it will burn with a yellow - orange flame.
2. Ba(OH)₂ - All barium compounds burn with greenflame. Barium hydroxide is also a barium compound. So it will burn with a green flame.
3. KOH - All potassium compounds burn with pink - lilacflame. Potassium hydroxide is also a potassium compound. So it will burn with a pink - lilac flame.
4. K₂CO₃ - All potassium compounds burn with pink - lilacflame. Potassium hydroxide is also a potassium compound. So it will burn with a pink - lilac flame.
5. BaO - All barium compounds burn with greenflame. Barium oxide is a barium compound. So it will burn with a green flame.

Conclusion

Color patterns with a flame test indicate the presence of a specific metal atom in a compound.