An acid is a substance which ionises (splits into ions) when placed in water, producing hydrogen ions (H+)
E.g. Sulfuric acid
H2SO4 H+ + HSO4-
Acids are classified as strong or weak depending on the number of H+ ions produced when in water.
Acids Waikawa∙
Ethanoic acid, citric acid, and tartaric acid are classified as weak acids because less than 100% of their molecules ionise when placed in water.
Hydrochloric (HCl), sulfuric (H2SO4), and nitric acids are classified as strong acids because 100% of their molecules ionise when placed in water.
Acid + Metal __________ + ___________
__________ + ___________
Acid + Carbonate ________ + ________ + ________
________ + ________ + ________
HCl + FeIron metalHydrochloric
acid
HCl + CaCO3Calcium carbonate
Hydrochloric acid
Acids Reactions
Acid + Bicarbonate _______ + _______ + _______
_______ + _______ + _______HCl + NaHCO3Calcium carbonate
Hydrochloric acid
Bicarbonates have the same products as carbonates when reacted with acids.
Bicarbonates just have an extra ‘H’
Bicarbonate ion: HCO3- Carbonate ion: CO3
-
Acids Reactions
Elements: Substances made up of 1 type of atom, e.g. diamond (C only).
e
A # = # of p (= to # e-)
M # = # of p + # of n
++
e-
e-
Symbol
Arranged in P.T. in order of A #
Groups (e- config)
Perio
ds (#
E le
vels
)
p (+ve)
1st E level
n (Ø)
e- (-ve) [O.N.E]
123
1 32
Atoms
e- arrangement
1 22 83 84 2
E le
vel
Max # e-Each element in period = same # E levels for e-s. 1st + last element = v. diff. b/c diff. in e- + p #
Elements in same group = similar properties b/c all have same # of e- in v.E level
e-
e-17p18n
e-e-
e-e-e-e-
e-e-
e-e-e-
e-e-
e-e-
3rd shell (also v.shell)
e- arrangemente.g. Cl atom: 2, 8, 7
Cl- ion: 2, 8, 8
p = 17; e = 17; n = 18
e-
e-11p12n
e-e-
e-e-
e-e-
e-e-e-
Na
Atoms lose or gain e- in order to achieve a full v.shell and be in a ∴ lower, more energetically favourable state
e-
e-17p18n
e-e-
e-e-e-e-
e-e-
e-e-e-
e-e-
e-e-
p = 11; e = 11; n = 12
Clnucleus (p + n)
{
1st shell (or E level)
2nd shell
Shells/ E levels: Found at diff. distances from nucleus
Ion formation: Atoms become ions. Ion = atom w/ + or – electrical charge.
e- is transferred
e-
e-11p12n
e-e-
e-e-
e-e-
e-e-
e-
Na+
p = 11; e = 10; n = 12
p = 17; e = 18; n = 18Cl-Ion charge =
diff. in p & e- #
e.g. Cl- = 1 more -ve e- than +ve p. charge = 1- ∴
Ions
Ionic compounds (salts): Ions with oppos. charges are electrostatically attracted to one another.
Na+ Cl-e.g. Ion w/ 1 +ve charge is electrostatically ∴attracted to an ion w/ 1 –ve charge ( 1:1 ratio)∴
NaClChemical formulaMust be in correct order and ratio Metal 1st
Non-metal 2nd
1:1 ratio
(Polyatomic ions)*brackets
OH- NO3-
HCO3- SO4
2-
CO32- NH4
+
Shows amount of atoms in substance, e.g. 1 Na+ and 1 Cl-
Indicators: Used to indicate if substance = acid or base. They ∆ colour according to pH. e.g. litmus/ U.I
∆ colour depending on amount of OH- / H+ produced
Acids
# indicating acidity/alkalinity
Ionises to produce H+ ions when placed in H2O
Weak/ dilute. ac: produce small amounts of H+. (<100% ionise).
Strong/ conc. ac: produce large amounts of H+. (100% ionise).
e.g. H2SO4 → H+ + HSO4-
(Put in H2O)Strong ac = many H+
produced. Many H+
turn U.I red
Reactions