Mixtures And Chromotography Flashcards
Q
A
What is a mixture in chemistry?
A mixture is made up of separate elements or compounds mixed together without chemical bonds.
How can the parts of a mixture be separated?
Through physical methods like filtration, crystallization, simple distillation, fractional distillation, and chromatography.
Name an example of a gas mixture.
Air, which contains mainly nitrogen, oxygen, carbon dioxide, and argon.
What are the properties of a mixture compared to its separate parts?
A mixture’s properties are just a mix of the separate parts, and individual substances in a mixture retain their properties.
Give an example of a mixture showing separate properties of its components.
A mixture of iron powder and sulfur powder retains properties of both—iron remains magnetic, and sulfur is yellow.
What is chromatography?
Chromatography is a technique for separating substances in a mixture based on their movement through a solvent.
What is the purpose of a pencil line in paper chromatography?
To mark the starting point because pencil marks are insoluble and won’t dissolve in the solvent.
How does the solvent affect paper chromatography?
The solvent seeps up the paper, carrying the ink with it and separating the dyes.
Why do different dyes separate on the chromatography paper?
Each dye moves up the paper at a different rate depending on its solubility in the solvent.
What happens to dyes that are insoluble in the solvent?
They stay at the baseline and do not move up the paper.
What is the final result in paper chromatography called?
The pattern of spots called a chromatogram.
Explain why you shouldn’t use a pen to draw a line on the filter paper for paper chromatography.
Ink from a pen can dissolve in the solvent and interfere with the results.
