A current of 45A is passed through a solution of gold salt for 1hour 45 minutes;
Calculate
(a)The mass of gold deposited
(b)The number of moles of gold deposits d
(c)If the same current is used, find the time taken for 5.5g of gold to be deposited (Au=197, 1F=96500)
See your previous post, "Joy."
I worked this for Joy a few hours ago. Here is the link.
https://www.jiskha.com/questions/1866671/a-current-of-45a-is-passed-through-a-solution-of-gold-salt-for-1-hour-45-minutes-calculate
if the same current is used to find the time taken for 5.5g of gold to be deposited
To find the answers to these questions, we can use Faraday’s laws of electrolysis. According to the laws, the mass of an element deposited during electrolysis is directly proportional to the quantity of electricity passed through the solution.
(a) Calculate the mass of gold deposited:
Step 1: Calculate the total charge passed.
We know that current (I) = 45 A (given) and time (t) = 1 hour 45 minutes.
Convert 1 hour 45 minutes to minutes:
1 hour = 60 minutes
1 hour 45 minutes = 1 * 60 + 45 = 105 minutes
Total charge (Q) = Current (I) * Time (t) = 45 A * 105 minutes
Convert time to seconds:
105 minutes * 60 seconds/minute = 6300 seconds
Q = 45 A * 6300 seconds
Step 2: Calculate the number of moles of electrons passed.
1 mole of electrons = 1 Faraday = 96500 C (Coulombs)
Number of moles of electrons (n) = Q / 96500 C
Step 3: Calculate the mass of gold deposited.
The molar mass of gold (Au) is 197 g/mol.
Mass of gold deposited = Number of moles of electrons * Molar mass of gold
Substituting the values and calculating:
Q = 45 A * 6300 seconds
n = Q / 96500 C
Mass of gold = n * Molar mass of gold
(b) Calculate the number of moles of gold deposited:
Number of moles of gold deposited = Mass of gold deposited / Molar mass of gold
(c) Calculate the time taken for 5.5 g of gold to be deposited:
Step 1: Calculate the number of moles of gold.
Number of moles of gold = Mass of gold / Molar mass of gold
Step 2: Calculate the total charge required.
The molar mass of gold (Au) is 197 g/mol.
Q = Number of moles of gold * Molar mass of gold
Step 3: Calculate the time taken.
Time (t) = Q / (Current (I) * 96500 C)
Substituting the values and calculating:
Q = Number of moles of gold * Molar mass of gold
t = Q / (Current (I) * 96500 C)
Hope this helps you calculate the desired values!