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