Acids and Bases Year 10 Hcl and aluminium bomb Add bung rather than screw top?

What are Acids? Acids are common Some are dangerous and can burn your skin Some are safe to eat and drink Stomach acid helps digest food Brainstorm understanding of acids (examples, what they do, how to test) fizz dissolve dangerous, dissolve metal, burn skin Name some in kitchen Vinegar, wine gone off, citric acid, batteries What taste sour H/O what do you know abt acid and base cut n paste Read aloud H/O acid burns Zn + HCl in test tube with balloon over the top, floats can be lit (pop test) Hindenberg explosion

Acids Definition Examples A group of compounds which behave similarly All have low pH Turn Litmus paper RED All donate H+ ions in aqueous solution Examples Hydrochloric HCl Sulfuric H2SO4 Nitric HNO3 Ethanoic CH3COOH Demo 3 beakers add h20 pour into phenolpthaelin then base Mineral acids tend to be strong, donate lots H+ organic acids (carboxylic acids) are weak don’t fully dissociate Learn these names and formula you will be tested EXPT Fair test planning for carbonate missile

Acids A dilute acid has lots of water and a small amount of acid A concentrated acid has lots of acid and not much water so must be handled carefully A strong acid releases lots of H+ A weak acid releases fewer H+ Lesson 2 Write bomb equation NaHCo3 + CH3CooH -> Ch3CooNa +H20 + CO2 Aim to work out how to make the canister fly furthest. Can alter the amount of acid and trajectory angle. How do you ensure fair test. Discussion. Expt film canister and bicarbonate explosions who can get the furthest, FAIR TEST angle of trajectory, amount acid

What are Bases (Alkalis)? In our home we often use bases to clean things. Eg Bleach and toothpaste Some things are not acids or bases, we say that they are neutral. Eg Water Lesson 3 Kids write from board “Acid and base are opposite one neutralises the other” Toothpaste neutralises acids formed by plaque bacteria, bee sting (formic acid baking soda neutralise) Bases which are soluble in water are called alkalis (feel soapy as they turn oils on hands into soap) EXPT make soap see H/O

Bases Definition Examples A family of compounds that behave similarly Have a high pH Turn litmus BLUE All donate OH- Examples Ammonia NH3 Sodium Hydroxide NaOH Ammonia in household cleaners NH# forms NH4+ and oh- (hydroxide ion) in water NaOH in oven cleaner, drain cleaner (dissolves grease)

Measuring acid strength? To decide if something is an acid or a base we can use an indicator. Litmus and Universal Indicator are examples of indicators. They change colour depending on if they are in an acid or a base. Lesson 4 How do we test? Demo invisible writing use phenol pthaelin spray with alkali “create a colour PH scale” Indicators are extracted from plants (lichen) Ph is a measure of the conc of H+ in solution Chemicals which change colour in the presence of acids or bases EXPT universal indicator create rainbow in teams of 3 (H/O) colour ph scale naoh strong alkali, nh3 may need to dilute with water Homework bring in flower to make indicator

Working with Indicators Red litmus turns BLUE in the presence of Bases Blue litmus turns RED in the presence of acid Acids and bases react together in a NEUTRALISATION reaction Lesson 5/6 Demo frothing rainbow (KISS)?????????????????? Draw on board word equation Reactants -- Products, Acid + base --- salt + water eg HCl + NaOH - NaCl + H2O ALWAYS OBSERVE WHEN MIXING CHEMICALS SMELL< FIZZ< HEAT< COLOUR ETC EXPT H/O indicators worksheet work in groups (make own indicator) EXPT find Ph of everyday substances H/O WRITE UP CORRECTLY, conclusion BLUE ALKALI, RED ACID< GREEN NEUTRAL

Acid Reactions Acid + Base  Salt + Water Acid + Metal  Salt + Hydrogen Acid + Carbonate  Salt + Water + Carbon Dioxide Hydrochloric acids (HCl) form CHLORIDE salts Nitric acid (HNO3) forms NITRATE salts Sulfuric acid (H2SO4) forms SULFATE salts Lesson 7 Write then do the experment Hcl + NaOH -> NACl + H2O 2HNO3 + 2K -> 2KNO3 +H2 (note fizzing) H2SO4 + CaCO3 -> CaSO4 + H2O + CO2 (note fizzing) STALAGMITE formation limestone caves Taj mahal H/O Acids and bases rules revision H/O Mix and match overview

Acid Rain Consider Causes Effects Chemical equations natural human Effects buildings flora fauna health Chemical equations Prevention/Solution Lesson 8/9 (show acid rain ppt? research their own) RECAP was water neutral Why not Co2 in air dissolves to form carbonic acid h2co3 DEMO Marble chips added to H2SO4 OBSERVE fizz = gas Other Minerals dissolved sulfur dioxide, from power stations volcanoes forms h2so4 and nitrogen dioxide NO2 from car exhausts ACID RAIN Acid rain H/O and reading( poss read science world pg 256) CREATE POSTER causes of acid rain, chemical reaction involved, effect on buildings, plants , fish , humans include pictures, (might want flow diagram, mind map etc) PRESENT back to class

Testing Gases Hydrogen - Lesson 10 Mg + H2SO4 Zn + HCl pop test CaCO3 + HCl co2 MnO2 + H2O2 O2 kmn04 heated H/O Quiz

Testing Gases Hydrogen - POP TEST Carbon Dioxide – Explodes with a squeaky pop Carbon Dioxide – Mg + H2SO4 pop test CaCO3 + HCl co2 MnO2 + H2O2 O2 H/O Quiz

Testing Gases Hydrogen - POP TEST Explodes with a squeaky pop Carbon Dioxide – Limewater goes cloudy Oxygen – Mg + H2SO4 pop test CaCO3 + HCl co2 MnO2 + H2O2 O2 H/O Quiz

Testing Gases Hydrogen - POP TEST Explodes with a squeaky pop Carbon Dioxide – Limewater goes cloudy Oxygen – Relights a glowing splint Mg + H2SO4 pop test CaCO3 + HCl co2 MnO2 + H2O2 O2 Kids need to have summary of the tests H/O Quiz

Antacid Investigation NZ facts 2007 70% population get heartburn /GERD $9m on 1 brand! 3rd most widely prescribed medicine Which brand is the best? Lesson 11/12 Gastro Eosophageal Reflux disease Based on what you have learnt how do they work Stomach HCl, antacids are bases so neutralise Interact with drugs which are pH dependent Antifungal concentrations increased in presence of antacid – potential problems? EXPT Science world pg 255 find which is most effective g per g, extension cost per g data, which is the best value for money Create table on board for them to copy H/O NCEA style 1 questions H/O equations lots of practise word equations to formula equations balancing equations for excellerant

Identify Unknown Solutions ? ? Lesson 13 or 18 if extras are added H/O Unknown chemicals Work in groups to identify 4 solutions SAFETY no taste/smell Write up correctly

Rates of Reaction Factors increasing the rate of reaction Surface area Concentration Temperature Catalyst/Enzyme Pressure Extra Lesson? Reactions take place when particles collide, increase rate need to increase the amount of particles or how fast they are moving to increase the likelihood of a collission Video solid/ ribbons/powder Carbonate bombs more H+ available to react EXPT 1cm mg ribbon in 5ml acid 10C, 20C, 30C, 40C water bath (temp) PLOT GRAPH what time would it take 1cm piece to react at 70C And 2,4,6,8 cm ribbon surface area? H/O expt rate of reaction

Metals/periodic table , Element, compound, exo/endo