Question

Arrange the following 0.10 M solutions in order of decreasing pH (highest to lowest): NaCIO, KCI, HBr, NaBro, CH3NH2Br NaBro > NaCIO > KCI > CH3NH3Br > HBr NACIO > NaBro > KCI > CH3NH2Br > HBr CH3NH2Br > NaBro > NaCIO > KCI > HBr NaCIO > CH3NH2Br > NaBro KCI > HBr NaBro > CH3NH2Br > NaCIO > KCI > HBr

Answer 1

Answer :

Option first is the correct option.

Write in order of decreasing pH .

Lower the pH higher the acidic strength, higher the pH lower will be it's acidic strength.

HBr is the strongest acid among all so it's pH will be lowest .

CH​​​​​3​​​ NH​​​​​3 Br is salt of strong acid HBr and weak base CH​​​​​3​CH​​3 -NH​​2 . So overall it will be acidic in nature have pH less than 7 .

KCl is neutral salt , so pH will be approximately equal to 7

NaClO is salt of weak acid HClO and strong base NaOH , it's pH will be in basic region (>7) .

NaBrO is salt of weak acid HBrO and strong base NaOH , so it's pH will be in basic region (>7)

Among HClO and HBrO , HClO is strong acid than HBrO because of higher electronegativity of Cl than Br. Strong acid have weak conjugate base . So, conjugate base of HClO is of lower pH than conjugate base of HBrO . So, pH of NaClO is lower than NaBrO .

pH order : NaBrO > NaClO > KCl > CH​​​​​3 NH​​​​​3 Br > HBr.