Chemical Analysis Flashcards
(12 cards)
What is a pure substance?
A substance consisting of one type of element or compound.
How can pure substances be identified?
Melting and boiling point analysis, then compare to a reference set of melting point data.
What is a formulation?
A mixture that has been designed as a useful product.
What are examples of formulations?
Paints, medicines, cleaning agents and fuels.
How does chromatography separate a mixture?
Different substances are more attracted to the mobile phase than the stationary phase, so the more soluble the substance, the further it will travel.
How do you calculate the retention factor (Rf)?
Rf = distance moved by solute (substance (colour))÷ distance moved by solvent (water).
How can the retention factor be used to identify substances?
By comparing it to known retention factor values for pure substances.
What is the test for hydrogen gas?
Insert a little splint makes a ‘squeaky pop’ sound.
What is the test for oxygen gas?
Insert a glowing splint and it will relight.
What is the test for carbon dioxide gas?
Bubble through limewater, it turns cloudy.
What is the test for chlorine gas?
Insert damp litmus paper. It will first go red, then bleach to white.
What is a capillary tube?
A very thin, glass tube.
