Question

Consider 0.10 M solutions of the following substances. Rank the solutions in order of increasing pH where 1 is the solution with the lowest pH and 7 is the solution with the highest pH. Reference the K_a and K_b Tables , and think about the acid/base properties of each species present.
1 2 3 4 5 6 7  HCl
1 2 3 4 5 6 7  Ca(OBr)₂
1 2 3 4 5 6 7  CaCl₂
1 2 3 4 5 6 7  C₆H₅NH₂
1 2 3 4 5 6 7  H₂NNH₃Cl
1 2 3 4 5 6 7  KOH
1 2 3 4 5 6 7  H₃BO₃

Reference the Ka and Kb Tables, and think about the acid/base properties of each species present. For conjugate acid/base pairs, Kw= Ka x Kb. For salt solutions, remember: A. +1 and +2 metal ions generally have no acidic/basic properties. B. the conjugate bases of weak acids are weak bases (1 > Kb > 10-14). C. the conjugate bases of strong acids are worse bases than water (Kb < 10-14). D. the conjugate acids of weak bases are weak acids (1 > Ka > 10-14).

Incorrect.

Tries 3/45

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Answer 1

increasing order of pH :

  HCl < H₂NNH₃Cl < H₃BO₃ < CaCl₂ < C₆H₅NH_{2 <} Ca(OBr)₂ < KOH

   1            2                 3               4              5                   6              7

HCl is a strong acid . so lowest pH

H2NNH3Cl it is salt of strong acid and weak base . so pH < 7

H3BO3 is a weak acid . so pH < 7

CaCl2 is salt of strong acid and strong base. so pH = 7

C₆H₅NH2 is salt of weak acid and weak base . so pHsightly > 7

Ca(OBr)2 is a salt of strong base and weak acid . so pH > 7

KOH is strong base .s o pH nearly 13 to 14