Which species in each pair is a better oxidizing agent under standard-state conditions? (a) br2 au3+ (b) h2 ag+ (c) cd2+ cr3+ (d) o2 in acidic media o2 in basic media?

(a) Au³⁺;  (b) Ag⁺; (c) Cd²⁺; (d) O₂ in acidic media

Explanation:

You've had Trends in the Periodic Table. Now, here are Trends in Standard Reduction Potentials.

Thus, for each pair of half reactions, we need to look only at which one has the more positive standard reduction potential.

(a) Br₂/Au³⁺  

Au³⁺(aq) + 3e⁻ ⟶ Au(s)       1.498 V

Br₂(ℓ) + 2e⁻ ⟶ 2Br⁻(aq)      1.066 V

Au³⁺ is the stronger oxidizing agent.

(b) H₂/Ag⁺  

Ag⁺(aq) + e⁻ ⟶ Au(s)          0.7996 V

H₂(g) + 2e⁻ ⟶ 2H⁻(aq)      -2.33      V

Ag⁺ is the stronger oxidizing agent.

(c) Cd²⁺/Cr³⁺  

Cd²⁺(aq) + e⁻ ⟶ Cd(s)      -0.4030 V

Cr³⁺(aq) + 3e⁻ ⟶ Cr(s)      -0.744   V

Cd²⁺ is the stronger oxidizing agent.

(d) O₂, H⁺/O₂, OH⁻  

O₂(g) + 4H⁺(aq) + 4e⁻ ⟶ 2H₂O(ℓ)         1.224 V

O₂(g) + H₂O(ℓ) + 4e⁻ ⟶ 4OH⁻(aq)       0.401  V

O₂ in acid is the stronger oxidizing agent.

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3