<span>i think its Uranium Dating </span>
Answer: Amount of Gallium = 0.127g
Explanation:
Electrolysis equation is:
Ga3+ + 3e- ------> Ga
To calculate the charge
t = 40.0 min = 40.0 x 60 s = 2400 s
time, t = 2400s
Q = I*t =
= 0.22A x 2400s
= 528 C
1 mol of Ga requires 3 mol of electron
1 mol of electron = 1 Faraday =96485 C
So,1 mol of Ga requires 96485x 3= 289455 C
mol of Gallium = 528/289455 = 0.00182 mol
Molar mass of Ga = 69.72 g/mol
mass of Ga = number of moles x molar mass
= 0.00182mol * 69.72
g/mol
= 0.127g
or you can use this direct formula
m=(current*time/Faraday's)*(molar mass/no of electrons transferred)
keeping in mind Ga3+ + 3e- → Ga
n=3
m=(It/F)*(mew/n)
m =(0.22 x 2400/96485) x (69.72/3)
m=0.127 g
There are 7 digits from decimal to 1st digit, and it's coming from right, so exponent will be in negative 7
In short, Your Answer would be: Option C) <span>6.75 × 10-7
</span>
Hope this helps!
Answer: 15768 seconds
Explanation: (50 years) x (365 da/yr) x (86,400 sec/da)
= (50 x 365 x 86,400) seconds
= 1.5768 x 10⁹ seconds