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Learning objective: To explain the reactions involving acids.
• Must: Describe the pH scale. Grade D• Must: Describe what happens during a
neutralisation reaction. Grade C• Should: Predict the name of products formed
during acid reactions. Grade B• Could: Write balanced symbol equations for the
acid reactions. Grade A
• Keywords: pH scale, salt, acid, word equation and balanced equation.
Let’s make a rainbow.
• Key skill used.• That you can read and
understand texts and take the appropriate action.
• As a team worker you can collaborate with others to work towards common goals.
pH scale.
• The pH scale tells us how acidic or alkaline a solution is. It is used to measure and help control the pH in a range of industries.
1. Indicators can be used to find out whether a solution is acid, alkaline or neutral
2. Universal Indicator can be used to find the pH of a solution
• Acid – red, pH less than 7• Neutral – green, pH = 7• Alkali – blue, pH greater than 7
pH scalepH scalepH scalepH scale
pH scale
Important acids.
• Hydrochloric acid – HCl(aq)
• Nitric acid– HNO3(aq)
• Sulfuric acid – H2SO4(aq)
• Make sure you learn and remember them!• What does the (aq) mean?
Acidic compounds in different states.
• Acids that are solids – citric and tartaric.• Acids that are liquids – nitric, sulfuric and
ethanoic.• Acids that are gases – hydrogen chloride.
Formula of some alkalis.
• Sodium hydroxide – NaOH• Potassium hydroxide – KOH• Magnesium hydroxide – Mg(OH)2
• Learn and remember these!
What is an acid?
• All acids contain hydrogen atoms.• When acids dissolve in water they produce
hydrogen ions, H+.• HCl(g) H+(aq) + Cl-(aq)
• That is why acids only behave like acids when they are dissolved in water.
What about alkalis?
• The same can be applied to alkalis.• This time it is the presence of the OH- ion that
makes a substance an alkali.• Strong alkalis like NaOH sodium hydroxide
split up completely.• NaOH(aq) Na+(aq) + OH-(aq)
Ionic equations
• The reaction between acids and alkalis can be represented by the following equation:
• Acid and alkali
• H+(aq) + OH-
(aq) H2O(l)
• Note that water is produced.
Learning objective: To explain the reactions involving acids.
• Must: Describe the pH scale.• Must: Describe what happens during a
neutralisation reaction.• Should: Predict the name of products formed
during acid reactions.• Could: Write balanced symbol equations for the
acid reactions.
• Keywords: pH scale, salt, acid, word equation and balanced equation.
Neutralisation – Hydrochloric acidNeutralisation – Hydrochloric acidNeutralisation – Hydrochloric acidNeutralisation – Hydrochloric acid
Neutralisation
Neutralisation – Sulphuric acidNeutralisation – Sulphuric acidNeutralisation – Sulphuric acidNeutralisation – Sulphuric acid
Neutralisation
Neutralisation – Nitric acidNeutralisation – Nitric acidNeutralisation – Nitric acidNeutralisation – Nitric acid
Neutralisation
Discover - Monitoring Neutralisation.
• Follow the instructions for AC6.13.
• Add 5 cm3 of HCl up to 35cm3 and then 1cm3 up to 45cm3
• Record your results and plot the graph.
• Make sure you wear goggles.
• Key skills• Read and understand
texts and take appropriate action.
• Use appropriate mathematical procedures.
• Examine patterns and relationships.
• Team worker – collaborate with others to work towards common goals.
Strong acid/base titration.
This is the shapeof the curve when a strong acidis reacted with a strong base.
What do you noticeabout the shape?
Testing understanding.
• Click here for more examples of neutralisation reactions.
• Click here for more information and tests about acids and alkalis.
Learning objective: To explain the reactions involving acids.
• Must: Describe the pH scale.• Must: Describe what happens during a
neutralisation reaction.• Should: Predict the name of products formed
during acid reactions.• Could: Write balanced symbol equations for the
acid reactions.
• Keywords: pH scale, salt, acid, word equation and balanced equation.
Discover - Investigating acids.
• Follow the instructions for AC6.3.
• Record your results and write word equations for each reaction.
• Make sure you are wearing goggles.
• Key skills.• Read and understand
texts and take appropriate action.
• Team worker – collaborate with others to work towards common goals.
1.Acids react with alkaline solutions to form a salt and water
• Hydrochloric acid produces chlorides
• Nitric acid produces nitrates• Sulphuric acid produces
sulphates
Naming SaltsNaming SaltsNaming SaltsNaming Salts
Neutralisation
Reactions of metals with acidsReactions of metals with acids
Copy and complete the following reactions:
1) Calcium + hydrochloric acid
2) Zinc + hydrochloric acid
3) Iron + hydrochloric acid
4) Lithium + sulphuric acid
METAL + ACID SALT + HYDROGEN
e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen
MgH Cl Mg
Cl
ClH
H
H Cl
Reactions of metal oxides with Reactions of metal oxides with acidacidA metal oxide is a compound containing a metal and oxide. They are
sometimes called BASES. For example:
Mg O NaNa
O
O
Al
AlO
O
Magnesium oxide
Sodium oxide Aluminium oxideMETAL OXIDE + ACID SALT + WATER
Copy and complete the following reactions:
1) Magnesium oxide + hydrochloric acid
2) Calcium oxide + hydrochloric acid
3) Sodium oxide + sulphuric acid
Mg OH Cl
Mg ClCl
HH OH Cl
Acid alkali reactionsAcid alkali reactionsA neutralisation reaction occurs when an acid reacts with an alkali. An alkali is a metal oxide or metal hydroxide dissolved in water.
ACID + ALKALI SALT + WATER
NaClH
H OH ClNa O
H
Copy and complete the following reactions:
1) Sodium hydroxide + hydrochloric acid
2) Calcium hydroxide + hydrochloric acid
3) Sodium hydroxide + sulphuric acid
4) Magnesium hydroxide + sulphuric acid
Reactions of metals carbonates with Reactions of metals carbonates with acidacid
A metal carbonate is a compound containing a metal, carbon and oxygen.
METAL CARBONATE + ACID SALT + CARBON DIOXIDE + WATER
Copy and complete the following reactions:
1) Magnesium carbonate + hydrochloric acid
2) Calcium carbonate + hydrochloric acid
3) Sodium carbonate + sulphuric acid
Mg H ClMg
Cl
Cl
HH
H Cl
C
O
O
OO
OO
C