Chemistry Flashcards
What is the equation for concentration (g/dm^3)
Conc = Mass(g)/volume(dm^3)
What is the equation for an Rf value in chromatography?
Rf = distance moved by substance/ distance moved by solvent
What is the equation for moles?
Moles = mass/Mr
What is the equation for the number of particles in a substance?
= moles x avagadros constant
What is the avagadros constant?
6.02x10^23
What is the equation for percentage yield?
% yeild = mass of product actually made/ maximum theoretical product possible made *100
What is the equation for atom economy?
= Mr of desired product/ Mr of all reactants *100
What is the equation for concentration using moles (mol/dm^3)?
Conc = moles / volume(dm^3)
What is the equation for the volume of gas at room temp?
Volume (dm^3) = moles*24
What are ions?
They are charged atoms
How are ions formed?
Ions are formed when atoms lose or gain electrons
What type of elements form ionic bonds?
A metal and a non metal
How are ionic bonds formed?
The metal atom transfers its outer shell electrons to the non metal
What are the properties of an ionic compound?
- High boiling + melting points
- Can conduct electricity when molten or dissolved
Why can’t ionic compounds conduct electricity when solid?
Because their ions are held in fixed positions and cannot move.
What type of elements form covalent bonds?
Two non-metals
What bonds are formed between a metal and a non-metal?
Ionic bonds
What bonds are formed between a non-metal and a non-metal?
Covalent bonds
How is a covalent bond formed?
The non-metals share their electrons.
What are the properties of simple covalent structures?
- They don’t conduct electricity
- They have low boiling + melting points
Why do simple covalent structures have low melting + boiling points?
Because they have weak intermolecular forces between the molecules which means they need little amount of energy to break the bonds
What are some examples of giant covalent structures?
Diamond, graphite, silicon dioxide and buckminsterfullerine
What element does diamond consist of?
Carbon
