JAMB - Chemistry (1981 - No. 30)
If 48,000 coulombs of electricity are required to discharge 0.5 mole of sodium from a molten sodium chloride mass, then the number of coulombs required to discharge 2 moles of lead from molten lead (ll) chloride is?
48,000
96,000
192,000
384,000
576,000
Penjelasan
48,000 coulombs are required to discharge 0.5 mole of Na
∴ 1 m will be discharged by 2 x 48,000 = 96,000 coulombs
2 moles of Na will be discharged by 2 x 96,000
= 192,000
For lead (Pb) two electrons are involved.
∴ Number or coulombs required to discharged 2 moles of Pb = 2 x 192,000 = 384,000 coulombs
∴ 1 m will be discharged by 2 x 48,000 = 96,000 coulombs
2 moles of Na will be discharged by 2 x 96,000
= 192,000
For lead (Pb) two electrons are involved.
∴ Number or coulombs required to discharged 2 moles of Pb = 2 x 192,000 = 384,000 coulombs