Definitions Flashcards
Ionic bonding
Ionic bonding is the electrostatic attraction of oppositely charged ions
High melting/ boiling point
Strong electrostatic forces of attraction take a lot of heat energy to overcome.
Covalent bonding
The electrostatic attraction between the nuclei (positive) of two atoms and a pair of electrons (negative) shared between them.
Melting/boiling point of simple molecular structures ?
Why?
Low melting/ boiling points because molecules are only very weakly attracted to other molecules through weak intermolecular forces, which require little energy to overcome.
An increase in the relative molecular mass of a substance
there are more intermolecular forces of attraction that need to be broken down, so more energy is needed to overcome these forces, causing the substance to have higher melting and boiling points.
Melting/ boiling point of giant covalent structures?
Why?
Solids with high melting and boiling points
made up of billions of atoms, all held together by many strong covalent bonds. To melt substance like this, these many strong bonds must be broken.
Metallic bonding
Metallic bonding is the electrostatic attraction between the positive ions and the delocalised electrons.
Why are metals good conductors of electricity?
The outer electrons in metals are delocalised and free to move around the ions
Reversible Reactions
Reactions that can go backwards and forwards
Hydrocarbon:
Crude oil is:
A compound of hydrogen and carbon only
A mixture of hydrocarbons
Fuel definition
Fuel is a substance that, when burned, releases heat energy.
Why is Carbon monoxide poisonous?
Carbon monoxide limits the capacity of blood to transport oxygen, depriving vital organs of oxygen
Empirical formula
Empirical formulae show the simplest whole number ratio of atoms in a compound.
Molecular formula
Molecular formulae show the actual number of atoms (and thus the actual formulae) of each element in a compound.
Exothermic
Heat energy is given out - reaction is hot
