Which, if any, of the following salts will be neutral in an aqueous solution?
A. NH4I
B. KCN
C. KBr
And…
In which choice are the 0.1 M aqueous solutions of salts ranked according to decreasing pH?
a) FeCl2, FeCl3, MgCl2, KClO2
1. MgCl2>FeCl3>KClO2>FeCl2
2. KClO2>MgCl2>FeCl2>FeCl3
3. FeCl2>KClO2>MgCl2>FeCl3
4. KClO2>MgCl2>FeCl3>FeCl2
b. NH4Br, NaBrO2, NaBr, NaClO2
1. NaBr>NaBrO2>NaClO2>NH4Br
2. NH4Br>NaBrO2>NaBr>NaClO2
3. NaBrO2>NaClO2>NaBr>NH4Br
4. NaBrO2>NH4Br>NaClO2>NaBr
Can anyone explain to me how you got to your answers? I’m so lost in Chem 106. >_<
1 Answer
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KBr because it is made via the reaction of a strong acid and a strong base
KOH + HBr –> KBr + H2O
KClO2 is a weak acid, MgCl2 is a slightly acidic salt, FeCl2 and FeCl3 are acidic salts, FeCl3 more acidic than FeCl2 due to # of Cl atoms
KClO2 > MgCl2 > FeCl2 > FeCl3
NaBrO2 > NaClO2 > NaBr > NH4Br
not 100% sure, has to do with the number of oxygens and the halide size. NaBr is a neutral salt, NH4Br = acidic salt with NH4+ grabbing an OH- from water leaving H+
HClO2 stronger acid than HBrO2 so, NaClO2 would be a weaker base than NaBrO2
