2.1.2 Compounds, formula and equations

What are ionic compounds formed from?

a metal and a non metal

Give the charge of an ionic compound

neutral

What charged ions do metals form?

positive

Are all positive ions metal ions?

no, there are some non-metal positive ions

What charge do non-metal ions form?

negative

Give the charge of group 1 ions

1+

Give the charge of group 2 ions

2+

Give the charge of group 3 ions

3+

Give the charge of transition metals

they have variable charges

Give the charge of group 7 ions

1-

Give the charge of group 6 ions

2-

Give the charge of group 5 ions

3-

What is used to indicate the charges of transition metals?

roman numerals

What are polyatomic ions?

ions made up of more than one type of atom

Give the chemical formula of ammonia ion

NH4+

Give the chemical formula of silver ion

Ag+

Give the chemical formula of zinc ion

Zn2+

Give the chemical formula of scandium ion

Sc3+

Give the chemical formula of hydroxide ion

OH-

Give the chemical formula of nitrate ion

NO3-

Give the chemical formula of manganate ion

MgO4-

Give the chemical formula of hydrogencarbonate ion

HCO3-

Give the chemical formula of hydrogensulfate ion

HSO4-

Give the chemical formula of carbonate ion

CO3 2-

Give the chemical formula of sulfate ion

SO4 2-

Give the chemical formula of sulfate (IV) ion

SO3 2-

Give the chemical formula of dichromate ion

Cr2O7 2-

Give the chemical formula of phosphte ion

PO4 3-

What name do positive ions end in?

-ium

What do (non polyatomic) negative ions end in?

-ide

What do (polyatomic) ions that contain oxygen end in?

-ate

Stops to writing the formulae of ionic compounds

• identify ions present and their charges

• balance charges

• write formula

What is the formula of magnesium hydroxide

Mg(OH)2

What is the formula of Aluminum nitrate?

Al(NO3)3

What is the chemical formula of noble gasses?

they exist as single molecules (e.g Ar)

How do non-noble gasses exist?

covalently bonded diatomic molecule

Give the chemical formula of nitrogen

N2

Give the chemical formula of sulphur

• S or

• S8

Give the chemical formula of hydrochloric acid

HCl

Give the chemical formula of sulfuric acid

H2SO4

Give the chemical formula of nitric acid

HNO3

Give the chemical formula of phosphoric acid

H3PO4

Give the chemical formula of ethanoic acid

CH3COOH

Give the chemical formula of sodium hydroxide

NaOH

Give the chemical formula of calcium hydroxide

Ca(OH)2

Give the chemical formula of copper (II) oxide

CuO

Give the chemical formula of ammonia

NH3

Give the chemical formula of sodium carbonate

Na2CO3

What is a symbol equation?

shorthand way of describing a chemical reaction using chemical symbols to show the number and type of each atom in the reactants and products

What is a word equation?

a longer way of describing a chemical reaction using only words to show the reactants and products

What does (s) mean?

solid

What does (g) mean?

gas

What does (l) mean?

liquid

What does (aq) mean?

• aqueous

• completely dissolved in water

What to remember when balancing equations?

• The number of each atom on each side of the reaction must therefore be the same

• Not to change any of the formulae

• To put the numbers used to balance the equation in front of the formulae

Steps to balancing equations

1. write the formulae of reactants and products

2. put in state symbols

3. Count the numbers of atoms in each reactant and product

4. Balance the atoms one at a time until all the atoms are balanced

How to balance combustion reactions for organic compounds?

1. carbon

2. hydrogen

3. oxygen

What are ions that aren’t present in a reaction called?

spectator ions