Answer:
0.2042 M is the original concentration of
(aq) in the titrating solution.
Explanation:
Mass of
= 0.217 g
Moles of 
1 mole of
have 2 mole of As and 1 mole of
have 1 mole of As.
So, from 1 mole of
we will have 2 moles of 
Then from 0.001096 mol of
:
of 

According to reaction, 1 mole of
reacts with 2 mole of cerium (IV) ions,then 0.002192 mol of
of cerium (IV) ions.
Volume of the acidic cerium{IV) sulfate = 21.47 ml =0.02147 L
1 mL = 0.001 L

![[Ce^{4+}]=\frac{0.004384 mol}{0.02147 L}=0.2042 M](https://tex.z-dn.net/?f=%5BCe%5E%7B4%2B%7D%5D%3D%5Cfrac%7B0.004384%20mol%7D%7B0.02147%20L%7D%3D0.2042%20M)
0.2042 M is the original concentration of
(aq) in the titrating solution.
the two process that occur in a cell are
oxidation: this is loss of electron by electrode. the metal electrode loaes electrons and get oxidized and forms ions
the ions get migrated to solution
Reduction: here the ions present in solution gains electron and get deposited on electrodes.
so gain of electrons is by ions
electrode gains electrons is where reduction occurs, and the half cell in which the electrode loses electrons is where oxidation occurs.
Because the sulfur ion has a negative two charge, the formula would be Fe2S3
The answer is C. Fluctuating.
Hope this helps!! ;))
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