Answer:
The correct answer is 12.58 grams.
Explanation:
Based on the given information, the electrolysis equation will be,
Al³⁺ + 3e⁻ ⇔ Al
1 mol of Al needs 3 moles of electron, and the value for 1 mole of electron is 96485 C.
Thus, 1 mole of Al needs 3 × 96485 C = 289455 C
Now the amount of charge passed is,
T = 2.5 hours
= 2.5 × 3600 s = 9 × 10³ s
Q = Current × Time
= 15A × 9 × 10³ s
= 13.5 × 10⁴ C
The moles of Al plated will be,
= 13.5 × 10⁴ / 289455
= 0.4664 mol
The molecular mass of Al is 26.98 grams per mole
Now the mass of Al will be,
= Number of moles × Molecular mass
= 0.4664 × 26.98
= 12.58 grams
