Topic 8: Acids and Bases Flashcards
Bronsted-Lowry Acid
proton (h+) donor
Bronsted-Lowry Base
proton (h+) acceptor
Lewis theory Acid
electron pair acceptor
Lewis Base
electron pair donator
enthalpy of neutralization
enthalpy change when an acid and a base react together to form 1 mole of h20
acid + metal reaction
salt + hydrogen
acid + base reaction
salt + water
acid + carbonate reaction
salt + water + carbon dioxide
neutralization reaction
exothermic reaction; when an acid and a base make salt and water
meausuring pH methods
- using pH meter
- using universal indicator
- electrical conductivity
- H+ concentration
strong acids
(weak conjugate bases; ionize and dissosiate completly in solution)
strong acid examples
HCl
HNO3
H2SO4
weak acid
partial dissociation/ionization in solution
strong conjugate bases
weak acid examples
partially ionize/dissociate
- H2CO3
- H3PO4
- CH3COOH
pH scale
pH + pOH= 14
7 is neutral
pH formula
-log (H+)
10^-pH
monoprotic vs. diprotic
monoprotic; 1 H ion (e,g, HCL)
diprotic; 2 H ions (e.g. H2SO4)
how to distinguish between a strong or weak acid
- electrical conductivity
- rate of reaction
- pH
causes of acid depostion
- all rain water naturally acidic due to dissolved CO2 (carbonic acid)
- wet acid deposition
- dry acid deposition
nitrogen oxides
(NOx)
origins; electiral storms, decomposition, bacteria ammonification, combustion
- react with water to form nitrous acid and nitric acid
- nitrogen and oxygen form nitrogen oxides
sulfur oxides
(SOx)
origins; volcanoes and fossil fuel comustions
-reacts with water to form sulfiric acid
reaction of s+ o process;
- SO2–> SO3–> Acids
effects of acid deposition on matierals
corrodes/oxidizes/erosion
effects of acid deposition on plants
prvents growth of plants
access to nutrients limited
damage to plant roots
blocks stomata for gas exchange
effects of acid deposition on water
eutrophication
ocean acidity
oxyggen depletion
animal suffer
effects of acid deposition on human health
respiratory illnesses + eye irritations
- possible risk of corroded/broken buildings
responses to acid deposition
- lower NOx and SOx formation (use of catalytic converters better for environment)
- switch to alternative energy soruces
- ‘liming’ of lakes to neutralize acidity (e.g. calcium oxide)
- post + pre combustion methods (hydrode sulfurization) and lower the temperature
litmus effect
acid: pink
base; blue
methyl orange effect
acid: red
base; yellow
phenolphthalein effect
acid; colourless
base; pink
precombustion methods of SO2
- hydrodesulfurization (HDS) is a catalytic process that removes sulfur from petroleum by reacting it with hydrogen to form H2S; this toxic gas is capture + converted into elemental sulfur for manufactural use of sulfuric acid
- for metal sulfide; wash sulfur by crushing it with coal + wahing with water
post combustion methods of SO2
- flue-gas desulfurization
- react CaO or CaCO3 with SO2 to form neutral product; Calcium Sulfate
reduction of NOx emissions
- Catalytic converters in vehicles; hot gases mixed with air and passed over platinum catalyst to convert toxic emisions to harmless products
2CO + 2NO—> 2CO2 + N2 - Lower temperature combustion
- formation of nitrogen monoxide reduced at lower temperature (reciruclate the exaust gases)
