So 6.02*10^22 is avogadro constant, which is the amount of atoms in one mole. If you look Xenon up in the periodic table you will find it's mass given <span>131,293, which is grams per 1 mole.
No water is lost because matter cannot be created nor destroyed
All copper atoms have atomic number 29: all their nuclei contain 29 protons. But they also contain uncharged particles called neutrons. In natural copper, the atoms are of two kinds. One has 29 protons and 34 neutrons in the nucleus; the other has 29 protons and 36 neutrons
Fe⁺² (aq) + 2e⁻ = Fe (s) ; E⁰ = - .44 V
Fe⁺³ (aq) + e⁻ = ® Fe²⁺ (aq) ; E⁰ = + .77 V
Reduction potential of second reaction is more , so it will take place , ie Fe⁺³ will be reduced and Fe will be oxidised .
So reaction in the combined cell will be
2Fe⁺³ + Fe = 3Fe⁺²
cell potential = .77 - ( - .44 )
= 1.21 V .
[H+] of basic solution = 10⁻¹¹·² = 6.31x10⁻¹² moldm³
[H+] of acidic solution = 10⁻²·⁴ = 3.98x10⁻³ moldm³
the diffrence is 3.9799x10⁻³ moldm³
hope that helps