Key definitions Flashcards
Why are noble gases unreactive
Atoms have a full outer shell of electrons. They don’t need to gain, lose or share electrons.
What is a hydrocarbon?
A compound containing hydrogen and carbon only
Unsaturated
An organic compound containing a carbon - carbon double bond.
Saturated?
An organic compound containing only single bonds between carbon atoms.
What is a catalyst?
A substance which speeds up a chemical reaction without being used.
How does a catalyst speed-up a reaction?
By providing a different pathway with a lower activation energy.
Two characteristics of a homologous series of organic compounds?
All members have:
The same chemical properties, a general formula, clear trend in physical properties.
Test for unsaturation?
Mix with bromine, changes from orange to colourless.
Test for hydrogen gas?
Burning splint, squeaky pop.
Test for pure water?
Find boiling point, pure water boils at exactly 100 degrees Celsius
Why does a simple molecular substance have a low melting point?
Little energy is need to overcome the weak inter-molecular forces.
Ionic bonding?
the electrostatic attraction between oppositely charged ions.
Why does an ionic compound have a high melting point?
It has a giant lattice structure.
Containing many strong electrostatic attractions between oppositely charged ions.
Lots of energy is need to break these bonds.
