Question

A current of 9.65A passing for 16min 40 seconds through a molten tin salt deposits 5.95g of tin. The oxidation state of tin in the salt is

Answer 1

+2

Answer 2

• 1. Calculate total time: Time (t) = 16 minutes 40 seconds = (16 * 60) + 40 = 960 + 40 = 1000 seconds.

• 2. Calculate total charge (Q): Charge (Q) = Current (I) × Time (t)
  Q = 9.65 A × 1000 s = 9650 C.

• 3. Calculate moles of electrons passed:
  Faraday's constant (F) = 96500 C/mol
  Moles of electrons (n_e-) = Q / F = 9650 C / 96500 C/mol = 0.1 mol e-.

• 4. Determine moles of tin deposited:
  Atomic mass of Tin (Sn) = 118.7 g/mol (standard value).
  Moles of tin (n_Sn) = Mass of tin / Atomic mass of tin
  n_Sn = 5.95 g / 118.7 g/mol ≈ 0.0501 mol.

• 5. Relate moles of electrons to moles of tin using oxidation state:
  Let the oxidation state of tin in the salt be 'x'. The electrochemical reaction for deposition is: Sn^(x+) + x e- → Sn(s)
  From the stoichiometry, 'x' moles of electrons are required to deposit 1 mole of tin.
  Therefore, Moles of tin deposited = (Moles of electrons passed) / x
  0.0501 mol = 0.1 mol / x

• 6. Solve for 'x':
  x = 0.1 / 0.0501 ≈ 1.996
  Rounding to the nearest whole number, x = 2.

The oxidation state of tin in the salt is +2.