ACIDS, BASES & SALTS National 5 Chemistry KNOCKHARDY PUBLISHING.
ACIDS, BASES AND SALTS A guide for A level students 2015 SPECIFICATIONS KNOCKHARDY PUBLISHING.
-
Upload
marie-granville -
Category
Documents
-
view
216 -
download
2
Transcript of ACIDS, BASES AND SALTS A guide for A level students 2015 SPECIFICATIONS KNOCKHARDY PUBLISHING.
ACIDS, BASESACIDS, BASESAND SALTSAND SALTSA guide for A level studentsA guide for A level students
20152015 SPECIFICATIONSSPECIFICATIONSKNOCKHARDY PUBLISHINGKNOCKHARDY PUBLISHING
INTRODUCTION
This Powerpoint show is one of several produced to help students understand selected topics at AS and A2 level Chemistry. It is based on the requirements of the AQA and OCR specifications but is suitable for other examination boards.
Individual students may use the material at home for revision purposes or it may be used for classroom teaching if an interactive white board is available.
Accompanying notes on this, and the full range of AS and A2 topics, are available from the KNOCKHARDY SCIENCE WEBSITE at...
www.knockhardy.org.uk/sci.htm
Navigation is achieved by...
either clicking on the grey arrows at the foot of each page
or using the left and right arrow keys on the keyboard
KNOCKHARDY PUBLISHINGKNOCKHARDY PUBLISHING
ACIDS, BASES AND SALTSACIDS, BASES AND SALTS
BRØNSTED-LOWRY THEORY
ACID proton donor HCl ——> H+(aq) + Cl¯(aq)
BASE proton acceptor NH3(aq) + H+(aq) ——> NH4+(aq)
ACIDS AND BASESACIDS AND BASES
ACIDS proton donors release H+ ions (protons) in aqueous solution
STRONG ACIDS
Hydrochloric HCl —> H+(aq) + Cl¯(aq) 1 replaceable H MONOPROTIC
Nitric HNO3 —> H+(aq) + NO3¯(aq) 1 replaceable H MONOPROTIC
Sulphuric H2SO4 —> 2H+(aq) + SO42-(aq) 2 replaceable H’s DIPROTIC
ACIDSACIDS
ACIDS proton donors release H+ ions (protons) in aqueous solution
STRONG ACIDS
Hydrochloric HCl —> H+(aq) + Cl¯(aq) 1 replaceable H MONOPROTIC
Nitric HNO3 —> H+(aq) + NO3¯(aq) 1 replaceable H MONOPROTIC
Sulphuric H2SO4 —> 2H+(aq) + SO42-(aq) 2 replaceable H’s DIPROTIC
WEAK ACIDS
Ethanoic CH3COOH(aq) CH3COO¯(aq) + H+(aq) MONOPROTIC
ACIDSACIDS
BASES proton acceptors react with acids by accepting H+ ions to form salts
e.g. carbonates K2CO3 MgCO3 CuCO3
hydrogencarbonates NaHCO3
metal oxides MgO ZnO CuOmetal hydroxides NaOH KOH Ca(OH)2
ammonia NH3
BASES AND ALKALISBASES AND ALKALIS
BASES proton acceptors react with acids by accepting H+ ions to form salts
e.g. carbonates K2CO3 MgCO3 CuCO3
hydrogencarbonates NaHCO3
metal oxides MgO ZnO CuOmetal hydroxides NaOH KOH Ca(OH)2
ammonia NH3
ALKALIS SOLUBLE BASES which release OH¯ (hydroxide ions) in aqueous solution
e..g. Soluble metal oxidessodium oxide Na2O + H2O(l) ——> 2Na+(aq) + 2OH¯(aq)
Soluble metal hydroxidessodium hydroxide NaOH ——> Na+(aq) + OH¯(aq)
potassium hydroxide KOH ——> K+(aq) + OH¯(aq)
Aqueous ammonia NH3(aq) + H2O(l) NH4+ (aq) + OH¯(aq)
or NH3(aq) + H+(aq) NH4+(aq)
BASES AND ALKALISBASES AND ALKALIS
SALTS Formed from the reaction between acids and baseshydrochloric acid makes CHLORIDESnitric acid makes NITRATESsulphuric acid makes SULPHATES / HYDROGENSULPHATES
SALTFORMATION A salt is produced when the H+ ion of an acid is replaced by...
a metal ion or the ammonium ion NH4
+
SALTSSALTS
SALTS Formed from the reaction between acids and baseshydrochloric acid makes CHLORIDESnitric acid makes NITRATESsulphuric acid makes SULPHATES / HYDROGENSULPHATES
SALTFORMATION A salt is produced when the H+ ion of an acid is replaced by...
a metal ion or the ammonium ion NH4
+
SUMMARYAcids react with...
metals to give a salt + hydrogenoxides of metals a salt + waterhydroxides of metals a salt + watercarbonates a salt + water + carbon dioxidehydrogencarbonates a salt + water + carbon dioxideammonia an ammonium salt
SALTSSALTS
Water ofcrystallisation • loosely bonded water molecules attached to salts
CuSO4.5H2OFeSO4.7H2ONa2CO3.10H2O
• the water can be driven off by heating
e.g. CuSO4.5H2O(s) ———> CuSO4(s) + 5H2O(l)
WATER OF CRYSTALLISATIONWATER OF CRYSTALLISATION
Water ofcrystallisation • loosely bonded water molecules attached to salts
CuSO4.5H2OFeSO4.7H2ONa2CO3.10H2O
• the water can be driven off by heating
e.g. CuSO4.5H2O(s) ———> CuSO4(s) + 5H2O(l)
HYDRATED copper(II) sulphate ANHYDROUS copper(II) sulphateBLUE CRYSTALS WHITE POWDER
WATER OF CRYSTALLISATIONWATER OF CRYSTALLISATION
Is a typical acid in dilute aqueous solution HCl ——> H+ (aq) + Cl¯(aq)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Hydrogen chloride is a colourless covalent gas; it is a poor conductor of electricity because there are no free electrons or ions present. It has no action on dry litmus paper because there are no aqueous hydrogen ions present.
Is a typical acid in dilute aqueous solution HCl ——> H+ (aq) + Cl¯(aq)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Hydrogen chloride is a colourless covalent gas; it is a poor conductor of electricity because there are no free electrons or ions present. It has no action on dry litmus paper because there are no aqueous hydrogen ions present.
If the gas is passed into water, the hydrogen chloride molecules dissociate into ions. The solution now conducts electricity showing ions are present. For each hydrogen chloride molecule that dissociates one hydrogen ion and one chloride ion are produced. The solution turns litmus paper red because of the H+(aq) ions.
Is a typical acid in dilute aqueous solution HCl ——> H+ (aq) + Cl¯(aq)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Hydrogen chloride is a colourless covalent gas; it is a poor conductor of electricity because there are no free electrons or ions present. It has no action on dry litmus paper because there are no aqueous hydrogen ions present.
If the gas is passed into water, the hydrogen chloride molecules dissociate into ions. The solution now conducts electricity showing ions are present. For each hydrogen chloride molecule that dissociates one hydrogen ion and one chloride ion are produced. The solution turns litmus paper red because of the H+(aq) ions.
Is a typical acid in dilute aqueous solution HCl ——> H+ (aq) + Cl¯(aq)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
HYDROGEN CHLORIDE HYDROCHLORIC ACID
colourless gas Appearance colourless soln.covalent molecule Bonding aqueous ionsHCl(g) Formula HCl(aq) poor Conductivity goodno reaction Dry blue litmus goes red
Is a typical acid in dilute aqueous solution HCl ——> H+ (aq) + Cl¯(aq)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Appearance Bonding and formula Conductivity Dry litmushydrogen chloride colourless gas covalent molecule HCl(g) poor no reactionhydrochloric acid colourless soln. aqueous ions HCl(aq) good goes red
Hydrogen chloride is a colourless covalent gas; it is a poor conductor of electricity because there are no free electrons or ions present. It has no action on dry litmus paper because there are no aqueous hydrogen ions present.
If the gas is passed into water, the hydrogen chloride molecules dissociate into ions. The solution now conducts electricity showing ions are present. For each hydrogen chloride molecule that dissociates one hydrogen ion and one chloride ion are produced. The solution turns litmus paper red because of the H+(aq) ions.
SUMMARY
Metals magnesium + dil. hydrochloric acid ——> magnesium chloride + hydrogen
Mg(s) + 2HCl(aq) ——> MgCl2(aq) + H2(g)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
1. WRITE OUT THE BALANCED EQUATION FOR THE REACTION
Metals magnesium + dil. hydrochloric acid ——> magnesium chloride + hydrogen
Mg(s) + 2HCl(aq) ——> MgCl2(aq) + H2(g)
Mg(s) + 2H+(aq) + 2Cl¯(aq) ——> Mg2+(aq) + 2Cl¯(aq) + H2(g)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
1. WRITE OUT THE BALANCED EQUATION FOR THE REACTION2. DILUTE ACIDS AND SALTS CONTAIN IONS; WATER, HYDROGEN & CARBON DIOXIDE DON’T
Metals magnesium + dil. hydrochloric acid ——> magnesium chloride + hydrogen
Mg(s) + 2HCl(aq) ——> MgCl2(aq) + H2(g)
Mg(s) + 2H+(aq) + 2Cl¯(aq) ——> Mg2+(aq) + 2Cl¯(aq) + H2(g)
cancel ions Mg(s) + 2H+(aq) ——> Mg2+(aq) + H2(g)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
1. WRITE OUT THE BALANCED EQUATION FOR THE REACTION2. DILUTE ACIDS AND SALTS CONTAIN IONS; WATER, HYDROGEN & CARBON DIOXIDE DON’T3. CANCEL OUT THE IONS WHICH APPEAR ON BOTH SIDES OF THE EQUATION
Metals magnesium + dil. hydrochloric acid ——> magnesium chloride + hydrogen
Mg(s) + 2HCl(aq) ——> MgCl2(aq) + H2(g)
Mg(s) + 2H+(aq) + 2Cl¯(aq) ——> Mg2+(aq) + 2Cl¯(aq) + H2(g)
cancel ions Mg(s) + 2H+(aq) ——> Mg2+(aq) + H2(g)
BasicOxides copper(II) oxide + dil. hydrochloric acid ——> copper(II) chloride + water
CuO(s) + 2HCl(aq) ——> CuCl2(aq) + H2O(l)
Cu2+O2-(s) + 2H+(aq) + 2Cl¯(aq) ——> Cu 2+ (aq) + 2Cl¯(aq) + H2O(l)
cancel ions O2- + 2H+(aq) ——> H2O(l)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Alkalis sodium hydroxide + dil. hydrochloric acid ——> sodium chloride + water
NaOH(aq) + HCl(aq) ——> NaCl(aq) + H2O(l)
Na+(aq) + OH¯(aq) + H+(aq) + Cl¯(aq) ——> Na+ (aq) + Cl¯(aq) + H2O(l)
cancel ions H+(aq) + OH¯(aq) ——> H2O(l)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Alkalis sodium hydroxide + dil. hydrochloric acid ——> sodium chloride + water
NaOH(aq) + HCl(aq) ——> NaCl(aq) + H2O(l)
Na+(aq) + OH¯(aq) + H+(aq) + Cl¯(aq) ——> Na+ (aq) + Cl¯(aq) + H2O(l)
cancel ions H+(aq) + OH¯(aq) ——> H2O(l)
Carbonates calcium carbonate + hydrochloric acid ——> calcium chloride + carbon dioxide + water
CaCO3(s) + 2HCl(aq) ——> CaCl2(aq) + CO2(g) + H2O(l)
Ca2+CO32-(s) + 2H+(aq) + 2Cl¯(aq) ——> Ca2+(aq) + 2Cl¯(aq) + CO2(g) + H2O(l)
cancel ions CO32- + 2H+(aq) ——> CO2(g) + H2O(l)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
Alkalis sodium hydroxide + dil. hydrochloric acid ——> sodium chloride + water
NaOH(aq) + HCl(aq) ——> NaCl(aq) + H2O(l)
Na+(aq) + OH¯(aq) + H+(aq) + Cl¯(aq) ——> Na+ (aq) + Cl¯(aq) + H2O(l)
cancel ions H+(aq) + OH¯(aq) ——> H2O(l)
Carbonates calcium carbonate + hydrochloric acid ——> calcium chloride + carbon dioxide + water
CaCO3(s) + 2HCl(aq) ——> CaCl2(aq) + CO2(g) + H2O(l)
Ca2+CO32-(s) + 2H+(aq) + 2Cl¯(aq) ——> Ca2+(aq) + 2Cl¯(aq) + CO2(g) + H2O(l)
cancel ions CO32- + 2H+(aq) ——> CO2(g) + H2O(l)
Hydrogen carbonates H+(aq) + HCO3¯ ——> CO2(g) + H2O(l)
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
SUMMARY
METALS react to give a salt + hydrogen
METAL OXIDES react to give a salt + water
METAL HYDROXIDES react to give a salt + water
CARBONATES react to give a salt + water + carbon dioxide
HYDROGENCARBONATES react to give a salt + water + carbon dioxide
AMMONIA reacts to give an ammonium salt
REACTIONS OF HYDROCHLORIC ACID REACTIONS OF HYDROCHLORIC ACID
© 2015 JONATHAN HOPTON & KNOCKHARDY PUBLISHING© 2015 JONATHAN HOPTON & KNOCKHARDY PUBLISHING
THE ENDTHE END
ACIDS, BASESACIDS, BASESAND SALTSAND SALTS