Chemical analysis

Created by

Simon

Cards (20)

What is a pure substance in chemistry?
Something made of only one type of substance
How does the melting point of a pure substance differ from that of an impure substance?
A pure substance has a sharp melting point, while an impure substance melts over a range of temperatures
What is a formulation?
A mixture designed for a specific purpose
Can you name some examples of formulations?
Fuels, cleaning agents, paints, medicines, alloys, fertilizers, and foods
What is chromatography?
A process for separating coloured mixtures
How is R<sub>f</sub> calculated in chromatography?
R<sub>f</sub> = distance moved by substance / distance moved by solvent
What is the test for hydrogen?
A lit splint gives a squeaky pop
What is the test for oxygen?
It re-lights a glowing splint
What is the test for carbon dioxide?
It turns limewater milky if bubbled through it
What is the test for chlorine?
It bleaches damp litmus paper
What is the test for magnesium ions?
It forms a white precipitate with sodium hydroxide solution
How can aluminium ions be distinguished from aluminium, calcium, and magnesium?
The white precipitate will dissolve with excess sodium hydroxide
What colour precipitates are formed when sodium hydroxide solution is added to solutions of copper(II), iron(II), and iron(III) ions?
Copper(II) ions form blue precipitate, iron(II) ions form green precipitate, iron(III) ions form brown precipitate
What is the test for a halide ion?
Add silver nitrate and nitric acid: chloride forms white precipitate, bromide forms cream precipitate, iodide forms yellow precipitate
What is the test for a carbonate ion?
Carbon dioxide gas is formed on addition of acid
What is the test for a sulfate ion?
A white precipitate is formed with hydrochloric acid and barium chloride
What colours are produced by different metals in a flame test?
Lithium - crimson; sodium - yellow; potassium - lilac; calcium - orange red; copper - green
What is instrumental analysis?
Using complex scientific equipment to identify substances
What are the three advantages of instrumental analysis?
Rapid, accurate, and sensitive
What information does flame emission spectroscopy produce?
The wavelength of light given off by a metal in a flame to identify the metal and its concentration