Acids, Alkalis And Rates Of Reaction Flashcards
What does the pH of a solution in water tell us ?
Whether it is acidic alkaline or neutral
What is the pH scale a measure of ?
The concentration of hydrogen ions
What is the pHof neutral substances ?
7
What is the pH of acids?
Less than 7
What is the pH of alkalis ?
Above 7
Name acids (not ones used in a lab) in order of closest to 7 to 0 (6)
Milk (6) Urine (5) Tomato juice (5) Vinegar (4) Lemon juice (3) Battery acid (0)
What type of substance is water in terms of bonding ?
Covalent substance
What is different about water?
Although water is a covalent substance, some water molecules break apart to make hydrogen and hydroxide ions
What is the name given when water breaks itself into hydrogen and hydroxide ions ?
Self ionisation
What kind of reaction is the self ionisation of water ?
Reversible
What is meant by equilibrium ( in terms of the self ionisation of water)
The concentration of the water molecules and ions are constant but not equal
What does any sample of water contain?
Millions of molecule of H2O
Only a few hydrogen and hydroxide ions
What is the Symbol for hydrogen ions?
H+
What is the symbol for hydroxide ions?
OH-
In PURE water what is the concentration of hydrogen and hydroxide ions and what does this mean in terms of its pH ?
Equal
PH7
What can be used to indicate the ‘concentration of’?
[….]
What are acids?
Compounds that produce extra hydrogen ions, When they dissolve in water
What does aq mean?
aqueous =dissolved in water
In terms of concentration what do acids have?
A greater concentration of hydrogen ion that hydroxide ions.
When water is added to acids , what happens to the : pH Concentration of hydrogen ions Concentration of hydroxide ions Conductivity
pH increases
Concentration of hydrogen ions decreases
Concentration of hydroxide ions increases
Conductivity decreases
What are acids usually made from?
Covalent substances that break into ions in water
Why do acids conduct electricity ?
They contain ions
What is the chemical equation for the break up of hydrochloric acid in water ?
HCl (g) —–> + -
H + Cl
What is the formula for hydrochloric acid?
And ionic formula
HCl
H+Cl-
What is the formula for sulphuric acid?
+ionic
H2SO4
(H+)2 SO4. 2+
What is the formula for nitric acid and ionic ?
HNO3
H+ NO3-
What is the formula for ethanoic acid and ionic ?
CH3 COOH
CH3 COO-H+
How can acids be made?
By dissolving non metal oxides in water
What is the chemical equation for the production of nitric acid?
NO2 + H2O > HNO3
What is the exception non metal oxide that does not produce an acid and why?
Silicon dioxide because it is insoluble (covalent network)
What are alkalis ?
Compounds that produce extra hydroxide ions when they dissolve in water
What is the chemical equation for the break up of sodium hydroxide in water?
NaOH (s) > Na+ (aq) + OH-
What do alkalis have in terms of concentration?
Greater concentration of hydroxide ions that hydrogen ions
What dissolve in water to produce alkaline solutions ?
Metal oxides and hydroxides
What is the chemical equation for the production of sodium hydroxide? (Balanced)
Na2O + H2O > 2NaOH
What is the pH scale?
A continuous range from below 0 to above 14
What effect do metal oxides have on water if they do not dissolve ?
No effect
Give an example of a metal oxide which does not dissolve in water ?
Copper oxide
What is special about ammonia ?
Give chemical equation and give the name of what it produces ?
It is the only covalent gas that can dissolve in water to produce an alkaline solution .
NH3 (g) + H2O > NH4OH (aq)
Ammonium hydroxide solution
What is the formula and ionic formula of sodium hydroxide?
NaOH
Na+OH-
What is the formula and ionic formula of potassium hydroxide ?
KOH
K+OH-
What is the formula and ionic formula for calcium hydroxide?
What is it also known as?
Ca(OH)2
Ca2+ (OH-)2
Lime water
What is the formula and ionic formula of ammonium hydroxide ?
NH4OH
NH4+ OH-
Name 2 gases which cause acid rain?
Sulfur dioxide and nitrogen dioxide
What is neutralisation ?
The reaction of acids with bases
What are the 3 bases ?
Metal hydroxides
Metal oxides
Metal carbonates
What are based that dissolve in water also known as?
Alkalis
What does the neutralisation of an acid with metal hydroxide produce ?
Salt + water
Give the word equation for the neutralisation of hydrochloric acid using sodium hydroxide ?
Sodium hydroxide + hydrochloric acid > sodium chloride +water
Give the chemical equation for the neutralisation of hydrochloric acid using sodium hydroxide
NaOH + HCl > NaCl + H2O
Give the ionic equation for the neutralisation of hydrochloric acid using sodium hydroxide
Na+OH- + H+Cl- > Na+Cl- + H2O
Once neutralised how can a soluble he obtained ?
By evaporation
What are spectator ions ?
Ions present during the reaction but remain unchanged by the reaction
What are the spectator ions in the neutralisation reaction between sodium hydroxide and hydrochloric acid ?
Sodium ions Na+ and chloride ions Cl-
By removing spectator ions from an ionic equation what remains ?
H+ + OH- > H2O
What is the salt formed from hydrochloric acid ?
Chloride
What is the salt formed from sulphuric acid ?
Sulphate
What is the salt formed from nitric acid ?
Nitrate
What is the salt formed from ethanoic acid ?
Ethanoate
What is produced during the neutralisation reaction between a metal oxide and an acid ?
Salt + water
What is the word equation for the neutralisation of sulphuric acid using copper(II)oxide ?
Copper(II)oxide + sulphuric acid > copper(II)sulphate + water
What is the chemical equation for the neutralisation of sulphuric acid using copper (II) oxide ?
CuO + H2SO4 > CuSO4 + H2O
What is the ionic equation for the neutralisation of sulphuric acid using copper (II) oxide ?
Cu2+O2- + (H+)2SO42- > Cu2+SO42- + H2O
Once neutralised how can excess insoluble reactant be removed ?
Filtration
What are the spectator ions for the neutralisation reaction between sulphuric acid and copper(II)oxide ?
Copper. Cu2+
Sulphate SO42-
What is the produced for the neutralisation of a metal carbonate and acid ?
Salt + water + carbon dioxide
What is the word equation for the neutralisation of nitric acid using calcium carbonate ?
Calcium carbonate + nitric acid > calcium nitrate + water + carbon dioxide
What is the chemical equation for the neutralisation of nitric acid using calcium carbonate ?
CaCO3 + 2HNO3 > Ca(NO3)2 + H2O + CO2
What is the ionic equation for the neutralisation of nitric acid using calcium carbonate ?
Ca2+ CO32- + 2H+NO3- > Ca2+ (NO3-)2 + H2O + CO2
What are the spectator ions for the neutralisation reaction between nitric acid and calcium carbonate ?
Calcium Ca2+
Nitrate NO3-
What does titration find the volume of ?
Volume of solutions involved in a reaction
For a chemical reaction to take place what must the particles of reacting substances do?
Collide with each other
What factors can increase the chance of successful collision ?
Increasing surface area/ decreasing particle size
Increasing concentration
Increasing temperature
Adding a catalyst