Identity of metal from electrolysis

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SUMMARY

The identity of the metal obtained from the electrolysis of a trivalent metal ion solution using a 5.0A current for 10 minutes, resulting in 1.18g of plated metal, is indium. The calculations involved determining the total coulombs (3000C) and converting this to moles of electrons (0.031092 mol). Dividing by three, due to the trivalent nature of the metal, yields 0.010364 mol of metal. The molar mass calculated from the mass and moles confirms that indium, with a molar mass of approximately 114.82 g/mol, is the closest match.

PREREQUISITES
  • Understanding of electrolysis and Faraday's laws
  • Knowledge of molar mass calculations
  • Familiarity with trivalent metal ions
  • Basic proficiency in unit conversions (coulombs to moles)
NEXT STEPS
  • Study the principles of electrolysis in detail
  • Learn about Faraday's laws of electrolysis
  • Explore the properties and applications of indium
  • Investigate other trivalent metals and their electrolysis behavior
USEFUL FOR

Chemistry students, electrochemists, and anyone interested in the practical applications of electrolysis in identifying metals.

TT0
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Homework Statement


A solution of a trivalent metal ion is electrolysed by a current of 5.0A for 10 minutes during which time 1.18g of metal was plated out. The identity of the metal is:

A cobalt
B chromium
C indium
D gallium
E bismuth

Relative atomic masses:
1 faraday = 96,486 coulombs.

Homework Equations


current*time=coulombs
coulombs/96486=faraday
1 faraday = 1 mol of electrons

The Attempt at a Solution


5.0*10*60=3000 coulombs
3000/96486=0.031092 mol of electron

Since trivalent metal ion, mol of metal = 0.031092/3 = 0.010364 mols

Trial and error by dividing 1.18 by molar mass shows indium is closest. 1.18/114.82 = 0.1028. Is this the correct answer?

Cheers!
 
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Yes, indium sounds good.
 
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Thanks!
 
To avoid trial and error use this formula:

Molar mass (g/mol)=mass(g)/number of moles(mol)
M=m/n
M= 1.18g/ 0.010364 mol
M=113.86 g/mol

Cd
113.86-112.41=1.45 difference
Indium
114.82-113.86=0.96 difference

So the closest answer is Indium
 

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