A current of 5.48 A is passed through a Cr(NO3)2 solution for 1.50 hours. How much chromium is plated out?
2016-05-11 5:22 pm
A current of 5.48 A is passed through a Cr(NO3)2 solution for 1.50 hours. How much chromium is plated out of the solution?
回答 (2)
2016-05-15 3:35 pm
✔ 最佳答案
Cr^2 2e- ---> Cr(s) 1.5 hours x 3600 sec/hr x 5.48 C/sec x 1 mol e-/96500 C x 1 mol Cr/2 mol e- x 52g Cr/mol Cr = 7.97 grams of Cr plated out.
2016-05-11 6:56 pm
Amount of charges
= Current × Time
= (5.48 A) × (1.50 × 3600 s)
= 29592 C
1 mole of e⁻ carries 96500 C (1 F) of charges.
No. of moles of e⁻ = (29592 C) / (96500 C/mol) = 0.30665 mol
Cr²⁺(aq) + 2e⁻ → Cr(s)
Mole ratio e⁻ : Cr = 2 : 1
No. of moles of Cr plated = (0.30665 mol) × (1/2) = 0.1533 mol
Molar mass of Cr = 52.00 g/mol
Mass of Cr plated = (52.00 g/mol) × (0.1533 mol) = 7.97 g
= Current × Time
= (5.48 A) × (1.50 × 3600 s)
= 29592 C
1 mole of e⁻ carries 96500 C (1 F) of charges.
No. of moles of e⁻ = (29592 C) / (96500 C/mol) = 0.30665 mol
Cr²⁺(aq) + 2e⁻ → Cr(s)
Mole ratio e⁻ : Cr = 2 : 1
No. of moles of Cr plated = (0.30665 mol) × (1/2) = 0.1533 mol
Molar mass of Cr = 52.00 g/mol
Mass of Cr plated = (52.00 g/mol) × (0.1533 mol) = 7.97 g
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