Chemical Analysis Flashcards
What is the test for hydrogen and its result?
The lit splint test, hydrogen gas burns with a squeaky pop
What is test for carbon dioxide and its result?
The gas is bubbled through limewater, if carbon dioxide is present, a white precipitate forms
What is the test for oxygen and its result?
Glowing splint placed in the gas will re-light if oxygen is present
What is the test for chlorine and its result?
Damp, blue, litmus paper turns white in the presence of chlorine
What is the test for an alkene and its result?
Add bromine water, if an alkene is present, it will turn from orange to colourless
What is the test for an acid or an alkali and it’s result?
Add an indicator, a colour change will be seen if an acid or alkali is present
What is the test for PH?
Add universal indicator and use the colour change to determine the pH
What is the test for an acid?
Add a metal carbonate and bubble, the gas produced through limewater. If it was an acid, a white precipitate will form.
What does the word pure mean in relation to substances?
A single element or compound not mixed with any other substances
What is a formulation?
A mixture of substances designed to be a useful product
What is important to remember about melting points and boiling points in relation to formulations?
Formulations do not have a fixed melting point or boiling point, by creating a formulation, the melting point will decrease and the boiling point will increase.
What is chromatography?
A process used to separate mixtures
What does chromatography involve?
A stationary phase, such as paper and mobile phase such as water. These two phases in separate chemicals based on the solubility in the mobile phase.
What affect solubility have on distance moved up the stationary phase?
The more soluble substance is the father. It moves up the chromatogram in a given time.
What is shown on the chromatogram for pure substance?
A pure substance will only show one result
How can we compare the chemical compounds that make up different chemicals?
Identical chemicals will move at the same rate, and therefore cover the same proportion of the chromatogram
What is the retention factor?
It is a quantitative data for chromatography.
What is the equation for the retention factor?
Rf= distance moved by chemical/ distance moved by solvent
What happens when electrons absorb energy?
Electrons can be promoted to higher energy levels in the atom. Atoms in the state are known as excited.