Question

When the Hg2+ concentration is 1.06 M, the observed cell potential at 298K for an electrochemical cell with the following reaction is 1.656V. What is the Cr3+ concentration? 3Hg2+(aq) + 2Cr(s)—13Hg(1) + 2Cr3+ (aq) Answer: M

Answer 1

In this Question we have to find con censation of cats [Mg + 2] = loom at 299k (T) Temperature falls nicsou [cats ] = ? 3ngot caq) + 2Cr(s) sugee)+ 3er +? caq) 3 In this elec to chemical cell ! Anock Coxidation ) Multiply by 2 because elechon balance Cerco s cotes + de - JxzE"centica) -479 - 074 - Crt3 (aq) cathode ( Reduction Reaction , Chege - Mg R)) x3 FCM" Img) = 0.35 12 Add ano de complete and cathode Elecho chemical for cell obtaining Reaction : 3Hq 2+ + 2CV () the 3M9 Ce) te or the 46 349 eaq) sing **cay) + 207 (8) sing c) + 26145 (ag of crt3 3 we have we have to For find Nernost concen bution Equation :-

tau = Fiel - 0.059 lopca as Reaction Quotient my number of moles of electrons pansferred in reaction proof of Nernest Equation: As we know that Gibbs free Energy: - enld) OG= BG= OG 1 RT -nf Feue And -nf Euil = n F Eo + RT en ca) ull - Fell = - Fell + RT enco) Eccle = tien - R'303 RT log co ) пE T-२१k R = 8.314 Il molk Es Far days constant (96500 c/mol) 0.059 Full - telu - rosa doga standard Ecell - Nernest Equation Ecathook - E mode For standard Elechochemical cell potential

Biell Füll For this Question : Cpg 11 May - 62682/06) 0.85 - (-0.74) - 0.85 + 0.74 .59 full = Now we find I crts] : Falu = teu n 0059 cu ous eoga noog moles sansferred in Reaction = 6 1. For example aA + bB Ł cet ad L a= [0] [ord of This is written only for gas (Reaction Quotient ) raja [B] b and aquous. For this electo Chemical Reaction : . 3 Mg +2 caa) + 20015) - 349 (2) +2 ent3 cay) Concetration of solid and eiquidi eiquid sa [Mgte] [Mg + 2] = 1.06 06 [crt3] = ?

Eau : tam 0.059 Tcrt372 ell orta song by mous toiven a full = 1165ry 1.656 = 1.59 - 0.059 [cat372 11.0673 kr +372 1.656 -1.59 = - 0.059 - 0.066 x6 = (prosj? cosa log (C++372 [1.06] 3 Liga C778) -6-71 = 10-6.71. Po e as į [cv+3]? [106] 1194 x 10-7 = I crt372 [lror]? [cate ] : rents] = 123 x 11ora 4.8 x 104 m