Ionic Compounds Flashcards
Name this complex ion and give its valency
NH4
ammonium ion
valency 1+
This is the CO3 complex ion. State its name and valency
Carbonate ion
valency 2-
What is the valency of a zinc ion?
Zn 2+
What is the formula of calcium fluoride?
CaF2
Ca is in group 2 - has valency of 2+
F is in group 7 - has valency of 1-
Use cross and drop….
What is the formula of magnesium oxide?
MgO
Mg is in group 2 - has valency of 2+
O is in group 2 - has valency of 2-
Use cross and drop…. anc cancel down to simplest ratio
Explain in terms of electrons how Na and O react to form sodium oxide
Two Na ions lose one electron each to form 2 Na+ ions
One oxygen atom gain these 2 electrons to form O2-
2[Na+] O2-
Na2O
Why do both metals and molten ionic compounds conduct electricity?
Both have charge particles which are free to move and carry charge
But, metals have negatively charge electrons which can carry charge and molten ionic compound have both postive and negative ions which can carry charge.
What are the two possible copper ions?
Cu 1+ and Cu 2+
Draw a cross dot diagram from Magnesium fluoride
Calcium loses two electrons to become Ca2+.
Is calcium oxidised or reduced?
oxidised
OIL RIG
Oxidation is loss of electrons
Draw the dot cross diagram for sodium oxide
remeber to use square brackets and to write in the charge of the ions
Draw the structure of an ionic compound
Alternating + and - ions in a giant (3D) lattice structure
Explain in terms of electrons how Mg and Cl react to form Magnesium chloride
Mg loses 2 electrons to form Mg2+
Two Cl atoms gain one electron each to form two Cl- ions
Mg2+ 2 [Cl1-]
Why is an ionic compound soluble in water but not soluble in an organic solvent?
Ionic compounds consist of charged ions and water molecules are polar (have charged ends on the molecule) this forms electrostatic attraction which can pull ionic compounds apart making them dissolve or dissociate
organic solvents do not have polar molecules (or molecules with charged ends) so they cannot attract and pull apart the ions in ionic compounds.
Draw a dot cross diagram for Magnesium oxide
What is the valency of the hydroxide ion
OH 1-
What is oxidation?
When an atom loses electrons OR gains oxygen
K1+ - potassium lost one electron
MgO - magnsium has gained oxygen
What is the formula of sodium nitride?
Na3N
Na is in group 1 - has valency of 1+
N is in group 5 - has valency of 3-
Use cross and drop….
Describe how electron shielding makes elements like potassium more reactive than lithium.
Potassium is a large atom
Potassium has more electrons (more electron shielding) between the nucleus and outer electrons and therefore has more repulsion on the outer electrons
The outer electron in potassium requires less energy to be remove
Therefore potassium is more reactive than lithium
Why is the melting point of MgO higher than the melting point of NaCl?
Mg ion has a charge of 2+ and oxygen ion has a charge of 2-
Na ion has a charge of 1+ and chloride ion has a charge of 1-
The ions in MgO have double the charge and therefore have a much greater electrostatic force of attraction
This requires more energy to overcome the ionic bonds in MgO than in NaCl
Why do metals and ionic compounds both have high melting points?
They both have many strong bonds in a giant structure
which requires a lot of energy to overcome
Fluorine atom gains an electron to become F1-.
Is fluorine oxidised or reduced?
reduced
OIL RIG
Reduction is gain of electrons
Name the complex ion and give its valency
OH
hydroxide ion
OH 1-
What is the difference between an ionic bond and a metallic bond?
both electrostatic attraction
both giant structure with many bonds
Both contain metal ions
BUT
Metallic is the attraction between a metal ions and delocalised electrons
Ionic is the attaction betwen a metal ion and a negative ion (or oppositely charge ions)
Why do ionic compounds conduct electricity when molten or in solution but not when it is in solid form?
When ionic compounds are molten or in solution the charge ions are free to move and carry charge
When ionic compounds are solid, the ions are not free to move and cannot carry charge.
What is the valency of a silver ion?
Ag 1+
Describe how electron shielding makes elements like fluorine more reactive than chlorine
Fluorine is a smaller atom
Fluroine has less electrons (less electron shielding) between the nucleus and outer electrons and so has less repulsion on the outer shell of electrons
The outer shell gains electrons more easily
Therefore fluorine is more reactive than chlorine
What is the valency of a carbonate ion
CO3 2-
What is the formula of sodium chloride?
NaCl
Na is in group 1 - has valency of 1+
Cl is in group 7 - has valency of 1-
Why do ionic compound have high melting points?
- There are many strong ionic bonds in a giant lattice structure
- requires a lot of energy to overcome
What are the two possible iron ions?
Fe 2+ and Fe 3+
Explain in terms of electrons what happens when Mg reacts with O to form MgO
Mg loses 2 electrons to form Mg2+
O gains two electrons from Mg to become O2-
Two electrons are transferred from Mg to O
What is the formula of magnesium nitride?
Mg3N2
Mg is in group 2 - has valency of 2+
N is in group 5 - has valency of 3-
Use cross and drop….
What is the valency of a nitrate ion?
NO3 1-
Explain what happens in terms of electrons when Na reacts with Cl to form NaCl
Na is from group 1 and loses one electron to become Na+
This electron is transferred to the chlorine atom which gains one electron to become Cl -
Na+ Cl-
What is the valency of a lead ion?
Pb 2+
Why are ionic compounds brittle?
The positive and negative ions are in layers and are arranged in an alternating pattern. This means that the positive ions are attracted to the negative ions and the whole compound is held together tightly.
If a set of layers are disrupted and slide in one direction, the positive ions are now postioned across from each other and they repel.
This breaks the layers apart - making the compound brittle
Draw the dot cross diagram for sodium chloride
Na loses one electron- now has a full outer shell
Cl gains one electron - now has a full outer shell
This is called the octet rule
What is the formula of sodium oxide?
Na2O
Na is in group 1 - has valency of 1+
O is in group 6 - has valency of 2-
Use cross and drop….
What is the valency of a sulfate ion?
SO4 2-
Why are metal malleable but ionic compounds are not?
Metals layers can slide but the delocalised electrons which form the metallic bond are not disrupted and they remain between the layers as they slide.
This means the metallic bond is not disrupted and the metal is still held together
Ionic compound layers are held together by the electrostatic attraction of oppositely charge ions. If these alternating ion layers are shifted on atom along, then similarly charge ions are now aligned and they repel and push the layers apart.
All salts have which type of bonding?
ionic bonding
The electrostatic attraction between oppositely charge ions
Which compound is ionic?
CH4 H2O MgCl2 NH3 CO2
Ionic compounds are formed when an electron is transferred from one atom to another.
Ionic compound consist of a metal from the left hand side of the periodic table which really wants to give electrons and a non-metal from the right hand side of the periodic table which really wants to gain electrons
CH4 H2O MgCl2 NH3 CO2
MgCl2 is the ionic compound- formed of a metal and non-metal
Calcium loses two electrons to become Ca2+.
Is calcium oxidised or reduced?
oxidised
OIL RIG
Oxidation is loss of electrons
What is the valency of a hydrogen ion?
H 1+
Define an ionic bond
electrostatic attraction between oppositely charge ions
What is the valency of an ammonium ion?
NH4 1+
Name the complex ion and give its valency
NO3
nitrate ion
NO3 1-
This is the complex ion, SO4. State its name and its valency
sulfate ion
valency is SO4 2-
