2.1.2 Compounds, Formulae And Equations Flashcards
What ions are formed by group 1? What happens to the electrons?
1+ (lose electron)
What ions are formed by group 1? What happens to the electrons?
1+ (lose electron)
What ions are formed by group 2? What happens to the electrons?
2+ (lose 2 electrons)
What ions are formed by group 3? What happens to the electrons?
3+ (lose 3 electrons)
What ions are formed by group 5? What happens to the electrons?
3- (gain 3 electrons)
What ions are formed by group 6? What happens to the electrons?
2- (gain 2 electrons)
What ions are formed by group 7? What happens to the electrons?
1- (gain an electron)
What is a binary compound?
A compound that only contains two elements.
How do you name a binary compound?
First element - keep same
Second element - change ending to -ide
What is a polyatomic ion?
An ion that contains atoms of more than one element bonded together.
Ammonium ion
(NH4)+
Hydroxide ion
(OH)-
Nitrate ion
(NO3) -
Carbonate ion
(CO3) 2-
Sulfate ion
(SO4) 2-
Silver ion
(Ag) +
Zinc ion
(Zn) 2+
Zinc ion
Zn (2+)
How do you write formulae?
Make each ions charges equal, to the other in the compound (swap, drop and cancel.)
What is empirical formulae?
The simplest whole number ratio of the number of atoms of each element in a compound.
How do you find empirical formulae?
Assume percentages are grams.
Find moles.
Divide by smallest number to get ratio.
Use ratio to write formulae.
Why do we use empirical formulae ?
Empirical formulae will always be the same, even as the size of crystals vary. (Unlike the molecular formula)
What is molecular formulae ?
The number of atoms of each element in a compound.
How do you find the molecular formula?
Find empirical formula.
Divide molar mass given by molar mass of empirical formulae.
Use this answer to multiply the empirical formula.
