Answer:
d. The gold(III) ion is most easily reduced.
Explanation:
The standard reduction potentials are
Au³⁺ + 3e⁻ ⟶ Au; 1.50 V
Hg²⁺ + 2e⁻ ⟶ Hg; 0.85 V
Zn²⁺ + 2e⁻ ⟶ Zn; -0.76 V
Na⁺ + e⁻ ⟶ Na; -2.71 V
A <em>more positive voltage</em> means that there is a <em>stronger driving force</em> for the reaction.
Thus, Au³⁺ is the best acceptor of electrons.
Reduction Is Gain of electrons and, Au³⁺ is gaining electrons, so
Au³⁺ is most easily reduced.
When we have:
Zn(OH)2 → Zn2+ 2OH- with Ksp = 3 x 10 ^-16
and:
Zn2+ + 4OH- → Zn(OH)4 2- with Kf = 2 x 10^15
by mixing those equations together:
Zn(OH)2 + 2OH- → Zn(OH)4 2- with K = Kf *Ksp = 3 x 10^-16 * 2x10^15 =0.6
by using ICE table:
Zn(OH)2 + 2OH- → Zn(OH)4 2-
initial 2m 0
change -2X +X
Equ 2-2X X
when we assume that the solubility is X
and when K = [Zn(OH)4 2-] / [OH-]^2
0.6 = X / (2-2X)^2 by solving this equation for X
∴ X = 0.53 m
∴ the solubility of Zn(OH)2 = 0.53 M
Answer:
11 protons
Explanation:
Sodium (Na)'s atomic number or proton number is 11, which means it contains 11 protons
Answer:
696 h
Explanation:
Let's consider the reduction of Cr³⁺.
Cr³⁺(aq) + 3e⁻ → Cr(s)
We can establish the following relations.
- The molar mass of Cr is 52.0 g/mol.
- 1 mol of Cr is deposited when 3 moles of e⁻ circulate.
- 1 mole of e⁻ has a charge of 96468 c (Faraday's constant).
- 1 A = 1 c/s
- 1 h = 3600 s
<em>How many hours will it take to plate 13.5 kg of chromium onto the cathode if the current passed through the cell is held constant at 30.0 A?</em>
