Chemistry 3.3 Flashcards
Reduction
GER: gain electrons
Oxidation
LEO: lose electrons (normally happens to metals)
Ionic bonding definition
Strong electrostatic attraction between oppositely charged ions.
Why do ionic compounds have high melting points?
Giant lattice/structure containing lots of ionic bonds.
Held together by lots of strong electrostatic forces of attraction (between oppositely charged ions)
Large amounts of energy needed to break apart these forced because they are strong.
Do ionic compounds conduct electricity as a solid?
No. To conduct electricity needs charged ions and able to move freely. Solid ionic compounds have charged ions but cannot move freely, stuck in fixed positions.
Charge on group 1 metals?
+1
Charge on Group 2 elements?
+2
Charge on Group 3 elements?
+3
Charge on Group 5 elements?
-3
Charge on Group 6 elements?
-2
Charge on Group 7 elements?
-1
Charge on Group 0/8 elements?
0 , therefore unreactive
Example: write the ionic half-equation for Calcium
Ca –> Ca2+ +2e-
How do you find the ionic compound formula of two ions?
Find the charges of the ions of each element. Ignore the + or -. Drop and swap the charges. If a charge is 1 then you don’t need to write 1 as subscript. Equal charges cancel out e.g. magnesium (+2) and Sulfur (-2) = MgS.
What are the ionic charges of metals normally?
Positive, they lose electrons
Describe the structure and bonding of..
Giant ionic lattice
Made up of positive (metal) ions and negative (non-metal) ions. MENTION FORMULA OF IONS. e.g. F-
Held together by strong electrostatic forces of attraction between oppositely charged ions.
Force acts in all directions so alternating ions.
Dot and cross diagram showing how electronic configurations change when they form ions
Draw a before and after.
Remember diatomic elements. (If non-metal is diatomic, put 2 in front of metal ion or draw 2 metal ions.).
Draw metal as crosses and non-metal as dots.
Arrow from metal electron to non-metal ion.
Do metals normally lose or gain electrons.
Lose electrons. Metals are normally oxidised.
Describe in terms of electrons what happens when (calcium) reacts to (chlorine) to form the ionic compound calcium chloride CaCl2
Calcium loses 2 electrons and 2 chlorine atoms each gain 1 electron. 1 Calcium atom and 2 chlorine atoms. To achieve a stable electron structure and to form ionic bonds.
Things to check when answering ‘give your answer in terms of electron transfer’ type questions
Make sure that all ions will have full outer shells.
Drop and swap to see if two metal atoms are needed for one non-metal or other way round.
Make sure that metal atoms are losing electrons and non-metal atoms are gaining electrons.
If it asks for the formulae of ions formed state the charge on each ion. (K+ and S2-)
Write charge outside of brackets for each ion.
Why do some ionic compounds have higher melting points?
Their ions have higher charges, making attraction between ions even stronger and harder to break.
When do ionic compounds conduct electricity?
As a liquid or in a solution.
Charge on silver
1+
Charge on copper
2+
Charge(s) on iron
2+ or 3+
Charge on lead
2+
Charge on zinc
2+
What word should you use when talking about the atoms or ions of an ion?
Always use the word ‘ions’.
