Chapter 9 + 10 Flashcards
pH Scale
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
6 > 1 Inc Acidity, 7 neutral, 8 > 15 Inc Alkaline
Measuring pH
Indicator In acid in alkali neutral
Phenolphthalein ,Colourless, pink, —-
Methyl orange, red , yellow, orange
Litmus Red Blue Purples
Universal Indicator, Red, Purple, ——
Reactivity series
K - Potassium - Please Na - Sodium - Stop Li - Lithium - Listening (to) Ca - Calcium - Classical Mg - Magnesium - Music Al - Aluminium - And Carbon - Carry All above H react Zn - Zinc - Zebras With Acids Fe - Iron - For Hydrogen - Hours
Cu - Copper
Ag - Silver
Au- Gold
Parent acid Formula Salt produced
Sulphuric H2SO4 Sulphate
Hydrochloric HCl Chloride
Nitric HNO3 Nitrate
Precipitation Reactions
A salt = Substance made from a cation of base + anion from acid
Usually formed from neutralisation but can be made through precipitation reaction
Example
AgNO3(aq) + NaCl(aq) > AgCl(s) + NaNO3(aq)
Precipitation reaction = cation from one solution has strong attraction with anion from another that they cannot be broken apart to be dissolved. When solutions are mixed a solid (precipitate) is formed
Ionic Equation - Only Cation + anion from 2 solutions in equations. Ag(aq) +Cl(aq) >AgCl(s)
Solubility Rules
Soluble:
- Nitrates
- Ammonium
- Group 1
- Group 7 except with Ag and Pb (pa)
- Sulphates except with Ba, Ca, pb (Bear Cap)
Insoluble:
- All Hydroxides (OH) except with group 1 and ammonium
- Carbonates except with Group 1 and ammonium
- Oxides tend to be insoluble except with group 1
Copper oxide = Black
Copper carbonate = Green
Titration
Used when all reactants are soluble and colourless
HCl(aq) + NaOH(aq) > Nacl(aq) + H20(l)
- rinse pipette with distilled water to get rid of impurities and NaOH
- Pipette 25cm³ of NaOH into a conical flask
- Add indictor (3 drops) - shows pH and when reaction is complete
- Use methyl orange so goes yellow (alkaline)
- Fill burette with acid
- record starting measurement
- Wait for solution to go orange pink (neutralisation)
- Work out amount of acid is needed and do again without indicator
Metal and Acids
Metal + Acid > Salt + Hydrogen
M(s) + 2H(aq) > M(aq) + H2(g) - Ionic Equation
Metal Oxide + Acid > Salt + Water
Metal oxide bases are insoluble
Bases = chemical that accepts Hydrogen
CuO(s) + H2SO4(aq) > CuSO4(aq) + H20(l)
Cuo + 2H + SO4 > Cu + SO4 + H2O
Cuo (s) + 2H(aq) > Cu(aq) + H2O(l)
Overall - M(s) + 2H(aq) > M(aq) + H2O(l)
Metal Hydroxides + Acid > Salt + Water
NaOH(aq) + HCl(aq) > NaCl(aq) + H20(l)
Na + OH + H + Cl > Na + Cl + H20
OH(aq) + H(aq) + H2O(l) - This is also the general ionic equation for this
Metal Carbonates + acid > Salt + water + CO2
CaCO3(s) + 2HCl(aq) > CaCl2(aq) + H2O(l) + CO2(g)
CaCO3 + 2H + 2Cl > Ca + 2Cl + CO2 + H2O
CaCO3(s) + 2H(aq)> Ca(aq) + CO2(g) + H20(l)
Overall - MCO3(s) + 2H(aq) >M+ H2O(l) + CO2(g)
Acids Bases
Acids - Proton( Hydrogen Ion) donator
Base - Proton (Hydrogen Ion) Acceptor
- Acids only dissolve in polar solvents like water
- Acids will dissolve in non-polar solvents (organic compounds) like hydrogen and carbon
Chapter 10 Summury
Chapter 10 Summary
1) Making Soluble Salts
- Chemical A(s) + Chemical B(aq) > Chemical C(aq) + chemical D (l)
- use of an excess chemical A to remove Chemical B (usually metal carbonate)
- once Chemical B is gone, filter to remove solid
- Partially evaporate water
- Allow to cool and crystallise
- Dry with Filter paper
Chapter 10 Summary Cont
2) Making Soluble Salts from titration
- Chemical A(aq) + chemical B(aq) > Chemical C(aq) + Chemical D(aq)
- Titration with indicator, calc average, repeat without indicator
- Partially evaporate solution
- Allow to cool and crystallise
- Dry with filter paper
Chapter 10 summary Cont
3) Making Insoluble Salts
- Chemical A(aq) + Chemical B(aq) + Chemical C(s) + Chemical D(aq)
- This reaction is a precipitation reaction
- Filter to obtain Chemical C
- Wash with Distilled water (Ok as its insoluble)
- Dry in a a hot oven (Cant crystallise it as doesn’t have any water in)
