Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Solution : Given,
Mass of Cu = 300 g
Molar mass of Cu = 63.546 g/mole
Molar mass of 
= 183.511 g/mole
- First we have to calculate the moles of Cu.
The moles of Cu = 4.7209 moles
From the given chemical formula, we conclude that the each mole of compound contain one mole of Cu.
So, The moles of Cu = Moles of = 4.4209 moles
- Now we have to calculate the mass of .
Mass of = Moles of × Molar mass of = 4.4209 moles × 183.511 g/mole = 866.337 g
Mass of = 866.337 g = 0.8663 Kg (1 Kg = 1000 g)
Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.
Answer:
The amount of energy liberated will be 49.38 J.
Explanation:
The amount of energy liberated (gibbs free energy) can be calculated using the following equation:
ΔG° = -nFε
n: amount of moles of electrons transfered
F: Faraday's constant
ε: cell potential
20.0 g of Zn is equal to 0.30 mol.
Two electrons are transfered during the reaction.
Therefore, n = 2x0.30 ∴ n = 0.60
ΔG° = - 0.60 x 96.485 x 0.853
ΔG° = 49.38 J
545mm Hg in Kilopascals is 72.6607
I hope this helps you. Good luck stay safe, healthy and, happy!<3
