Physical chemistry equations

Question 1

Na2S2O3 (aq) + 2HCl (aq)

Answer 1

SO2(aq) + S (s) + H2O (l) + 2NaCl (aq)

Question 2

CaCO3 (s) + 2HCl (aq)

Answer 2

CaCl2 (aq) + CO2 (g) + H2O (l)

Question 3

H2O2 (aq) + 2I- (aq) + 2H+ (aq)

Answer 3

I2 (aq) + 2H2O (l)

Question 4

2S2O32- (aq) + I2 (aq)

Answer 4

2I- (aq) + S4O62- (aq)

Question 5

Lithium fuel cell:

Answer 5

Li (s) → Li+ (s) + e– Eꝋ = -3V
Li+ (s) + CoO2 (s) + e– → Li+(CoO2 – (s) Eꝋ = +1 V
Overall: Li (s) + CoO2 (s) → Li+(CoO2)– (s) Eꝋcell ~ +3.5

Question 6

Alkaline hydrogen-oxygen fuel cell

Answer 6

2H2 (g) + 4OH– (aq) → 4H2O (l) + 4e– Eꝋ = -0.83 V
O2 (g) + 2H2O + 4e– → 4OH– (aq) Eꝋ = +0.40 V
Overall: 2H2 (g) + O2 (g) → 2H2O (l) Eꝋ = +1.23 V