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On passing 10 amperes of current for 50 minutes, 2.4 gm of a metal is deposited . The equivalent weight of the metal is |
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Answer» mula for equivalent weight : E mass of metal deposited on electrode: m = 2.4 gms current STRENGTH i = 10 A time duration t = 50 min = 3, 000 sec. charge = i t = 30, 000 Coulombs 96, 500 m = E * i * t E = 96, 500 * m / ( i t ) = 96, 500 * 2.4 / 30, 000 = 7.72 The atomic weight if the metal is univalent : 7.72 The atomic weight if the metal is divalent : valency 2: 15.42 ====================ALTERNATE way to do the above exercise:the charge : 10 A * 50 * 60 sec = 30, 000 Coulombs. equivalent to 30, 000 /1.602 * 10⁻¹⁹ = 1.8726 * 10²³ protons. So this many ions with SINGLE charge on them have travelled to the electrode.If the metal is a single charge carrying one (single valency) then: weight of a metal ion : 2.4 gm / 1.8726 * 10²³ = 1.253 * 10⁻²³ gm weight of one mole of metal ions : 1.253 * 10⁻²³ * 6.023 * 10²³ = 7.72 if the metal has valency 2 , then its atomic weight will be : 15.438 |
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