Download - Yr10 acids and bases
Acids and Bases
Year 10Year 10
What are Acids?What are Acids? Acids are commonAcids are common Some are Some are
dangerous and dangerous and can burn your skincan burn your skin
Some are safe to Some are safe to eat and drinkeat and drink
Stomach acid Stomach acid helps digest foodhelps digest food
explosion
AcidsAcids
Definition Definition • A group of compounds which behave similarlyA group of compounds which behave similarly• All have low pHAll have low pH• Turn Litmus paper REDTurn Litmus paper RED• All donate HAll donate H++ ions in aqueous solution ions in aqueous solution
ExamplesExamples• Hydrochloric HClHydrochloric HCl• Sulfuric HSulfuric H22SOSO44
• Nitric HNONitric HNO33
• Ethanoic CHEthanoic CH33COOHCOOH
AcidsAcids
A A dilute aciddilute acid has lots of water and a has lots of water and a small amount of acidsmall amount of acid
A A concentrated acidconcentrated acid has lots of acid has lots of acid and not much water so must be and not much water so must be handled carefullyhandled carefully
A A strongstrong acid releases lots of H acid releases lots of H++
A A weakweak acid releases fewer H acid releases fewer H++
What are Bases (Alkalis)?What are Bases (Alkalis)?
In our home we In our home we often use bases often use bases to clean things. to clean things. Eg Bleach and Eg Bleach and toothpastetoothpaste
Some things are Some things are not acids or not acids or bases, we say bases, we say that they are that they are neutral. Eg Waterneutral. Eg Water
BasesBases
DefinitionDefinition• A family of compounds that behave A family of compounds that behave
similarlysimilarly• Have a high pHHave a high pH• Turn litmus BLUETurn litmus BLUE• All donate OHAll donate OH--
ExamplesExamples• Ammonia NHAmmonia NH33
• Sodium Hydroxide NaOHSodium Hydroxide NaOH
Measuring acid strength?Measuring acid strength?
To decide if something is an acid or a To decide if something is an acid or a base we can use an indicator.base we can use an indicator.
Litmus and Universal Indicator are Litmus and Universal Indicator are examples of indicators.examples of indicators.
They change colour depending on if They change colour depending on if they are in an acid or a base.they are in an acid or a base.
Working with IndicatorsWorking with Indicators
Red litmus turns BLUE in the Red litmus turns BLUE in the
presence of Basespresence of Bases Blue litmus turns RED in the Blue litmus turns RED in the
presence of acidpresence of acid Acids and bases react together in Acids and bases react together in
a NEUTRALISATION reactiona NEUTRALISATION reaction
Acid ReactionsAcid Reactions
Acid + Base Acid + Base Salt + Water Salt + Water
Acid + Metal Acid + Metal Salt + Hydrogen Salt + Hydrogen
Acid + Carbonate Acid + Carbonate Salt + Water + Carbon Dioxide Salt + Water + Carbon Dioxide
• Hydrochloric acids (HCl) form CHLORIDE saltsHydrochloric acids (HCl) form CHLORIDE salts
• Nitric acid (HNONitric acid (HNO33) forms NITRATE salts) forms NITRATE salts
• Sulfuric acid (HSulfuric acid (H22SOSO44) forms SULFATE salts) forms SULFATE salts
Acid RainAcid Rain
Consider Consider • Causes Causes
naturalnatural humanhuman
• Effects Effects buildingsbuildings floraflora faunafauna healthhealth
• Chemical equationsChemical equations• Prevention/SolutionPrevention/Solution
Testing GasesTesting Gases
Hydrogen -Hydrogen -
Testing GasesTesting Gases
Hydrogen - POP TESTHydrogen - POP TEST
• Explodes with a squeaky popExplodes with a squeaky pop
Carbon Dioxide – Carbon Dioxide –
Testing GasesTesting Gases
Hydrogen - POP TESTHydrogen - POP TEST
• Explodes with a squeaky popExplodes with a squeaky pop
Carbon Dioxide – Limewater goes Carbon Dioxide – Limewater goes
cloudycloudy
Oxygen – Oxygen –
Testing GasesTesting Gases
Hydrogen - POP TESTHydrogen - POP TEST
• Explodes with a squeaky popExplodes with a squeaky pop
Carbon Dioxide – Limewater goes Carbon Dioxide – Limewater goes
cloudycloudy
Oxygen – Relights a glowing splintOxygen – Relights a glowing splint
Antacid InvestigationAntacid Investigation
NZ facts 2007NZ facts 2007
• 70% population get 70% population get
heartburn /GERDheartburn /GERD
• $9m on 1 brand!$9m on 1 brand!
• 33rdrd most widely most widely
prescribed medicineprescribed medicine
Which brand is the Which brand is the
best?best?
Identify Unknown SolutionsIdentify Unknown Solutions
Rates of ReactionRates of Reaction
Factors increasing the rate of Factors increasing the rate of reactionreaction
•Surface areaSurface area•ConcentrationConcentration•TemperatureTemperature•Catalyst/EnzymeCatalyst/Enzyme•PressurePressure
Metals/periodic tableMetals/periodic table
, Element, compound, exo/endo, Element, compound, exo/endo