Chlorinated solvents such as carbon tetrachloride (CCl4) can be degraded by anaerobic microbial organisms in a process known as reductive dechlorination where Cl atoms are removed and replaced with H atoms. For example:
CCl4 + H+ + 2e- = CHCl3 + Cl- E=0.67 volt
Would anaerobic microbes grow better using CCl4 or nitrate as electron donors in their oxidation of formate (HCOO-) to carbon dioxide? Support your answer using thermodynamic calculations.