The standard Gibbs formation energy of ions Saturated Solution of B CB,S Diluted Solution of B CB=1.0 mol.L-1 Stable simple substances Pure Compounds B

About biochemical standard state and the thermodynamic equilibrium constant CΘ(H+)=[H+]=10-7mol.dm-3 A+B ↔ C+ xH+ No effect on

6.6 Effect of environmental conditions on the chemical reaction equilibrium (1) Temperature G-H equation The van’t Hoff equation

Le Chatelier’s principle Endothermic: increasing temperature favours the products Exothermic: increasing temperature favours the reactants Le Chatelier’s principle A system at equilibrium, when subjected to a disturbance, responds in a way to minimise the effects of the disturbance.

a plot of - ln K against 1/T has a slope of ΔrHm/R. Integration equation: a plot of - ln K against 1/T has a slope of ΔrHm/R.

Approximate Calculation about Equilibrium at different temperature Tr=298K Approximation

Increasing temperature benefit the reaction Decreasing temperature benefit the reaction Turning temperature

(2)Pressure Only related to temperature Only related to temperature, too

Le chatelier principle KP , KC not related to P B, the gaseous substance P↑, Kx↑, move to right Kx related to P: Le chatelier principle

(3) Effect of inert gases on chemical equilibrium Gases do not take part in the reaction, such as N2 ( )T,V no change/ ( )T,P similar to p decreasing =0 No effect on Kn ↑ ↑ Equilibrium move to right

6.6 Contemporary chemical equilibrium The product of the previous reaction is the reactant of the latter reaction At equi. state

=0 (1),(2) 1-x 1-x x x X=0.039

Biochemical reactions

G+Pi↔G6P+H2O 11.6 0.5 ATP+H2O↔ADP+Pi -32.5 -30.9 298K ΔG0/KJ.mol-1 ΔH0/KJ.mol-1 G+Pi↔G6P+H2O 11.6 0.5 ATP+H2O↔ADP+Pi -32.5 -30.9 G+ATP↔G6P+ADP -20.9 -30.4 Kc=4630 Kc=2880 310K

Coupling reactions METABOLIC CYCLES

The overall reaction Glucose+2Pi+2ADP↔2Lactate+2ATP+2H2O ΔG0=-124.4kJ.mol-1 Glucose(s)+6O2↔6CO2(g)+6H2O(l) ΔG0=-2878.4kJ.mol-1 ΔH0=-2801.6kJ.mol-1

Direct synthesis of ATP In 1961, Peter Mitchell proposed that the synthesis of ATP occurred due to a coupling of the chemical reaction with a proton gradient across the membrane He received a Nobel Prize for his work

Mechanisms of direct synthesis of ATP ATP+H2O↔ADP+Pi -32.5 kJ.mol-1 ADP+Pi ↔ ATP+H2O nH+(out)↔nH+(in) n=3 A pH differential of one unit gives a free energy change of -17.1 kJ.mol-1 Membrane potential -100mV

Homework Y: P138 39; P139 42, 43 Discussion how the temperature, pressure affect the Haber reaction equilibrium, give out the approach increasing the yields of NH3. N2+3H2↔2NH3 The Haber process, also called the Haber–Bosch process Haber Bosch