Acell composed of a platinum indicator electrode and a silver-silver chloride reference electrode in a solution containing both fe2+ and fe3+ has a cell potential of 0.727 v. if the silver-silver chloride electrode is replaced with a saturated calomel electrode (sce), what is the new cell potential?

0.683 V

Explanation:

The saturated calomel electrode (SCE) is based on the following reaction:

0.5 Hg₂Cl₂(s) + e⁻ → Hg(l) + Cl⁻

If compared to the Standard Hydrogen Electrode, this electrode has a potential of +0.241 V, while the silver-silver chloride has a potential of +0.197 V.

So the new cell potential would be:

0.727 - (0.241 - 0.197) = 0.683 V

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"