Redox reactions

• accepts electrons from another reagent • is reduced

• gives electrons to another reagent • is oxidised

• salt bridge • high resistance voltmeter • metal electrodes • aqueous solution (1moldm^-3) • standard conditions 298K, 100KPa

• produces more electrons • oxidised • stronger reducing agent • equilibrium shifts to the left

• the potential difference of a cell • when the electrode is connected to the standard hydrogen electrode • under standard conditions

right E- left E

• equilibrium will shift to counteract the change • changes concentration of electrons

• must have positive cell potential • rate of reaction has no effect

• low density • high reactivity • high electrode potential

• toxic • fire risk- high reactivity

• energy from reaction of fuel with oxyegn • fuel- hydrocarbon, hydrogen or alcohol • creates a voltage • acidic or alkaline solution

• greater efficiency • only H2O formed- not polluting

• H2 difficult to store • H2 difficult to manufacture initially

• gains electrons • reduced • stronger oxidising agent • equilibrium shifts to the right

• manganate MnO4- is oxidising agent • reduced to Mn^2+ • Fe^2+ is reducing agent • oxidised to Fe^3+ • turns from purple to pink

• dilute sulfuric acid • doesnt oxidise • doesnt react with manganate ions

• S2O3^2- is reducing agent • oxidised to S4O6^2- • I2 is oxidising agent • reduced to I-

yellow to blue-black