Question

Due. Ilurs. Nov. 1, 2019 1. a. Using Pauling's Rules estimate the pKj values for each of the following acids. List the following acids in order of acid strength in aqueous solution: HReO4 HzSbO4 H2SO3 H2SO4 b. Which of the following oxides are likely to be acidic, basic or amphoteric? Write balanced equations for their reaction with water and acid or base if amphoteric). i) As2O3 ii) TeO2 iii) VO

Answer 1

Answer 1a)

According to Pauling rules, if oxoacid is (O)_pE(OH)_q,

pK1 = 8 - 5p

i) HReO₄ = O₃Re(OH)

pK1 = 8 -5(3) = -7

ii) H₃SbO₄ = OSb(OH)₃

pK1 = 8 -5 = 3

iii) H₂SeO₃ = OSe(OH)₂

pk1 = 8 -5 = 3

iv) H₂SeO₄ = O₂Se(OH)₂

pK1 = 8 -5*2 = -2

Answer 1b)

I) As₂O₃ is amphoteric.

As base : As₂O₃ + 6HCl ----> 2AsCl₃ + H₂O

As acid : As₂O₃ + 6NaOH -----> 2Na₃AsO₃ + 3H₂O

ii) TeO₂

As base : 2TeO₂ + 2HCl ----> Te₂O₃Cl₂ + H₂O

As acid : TeO₂ + 2NaOH -----> Na₂TeO₃ + H₂O

iii) VO

It is neutral oxide.