Question #42a55

1 Answer
Jan 20, 2015

To determine, you look at the strength of the underlying acid and base. The stronger one defines the pH of the salt.

#NaCl# strong acid (#HCl#) and strong base (#NaOH#)
Result: neutral

#NaHCO_3# weak acid (#H_2CO_3#) strong base (#NaOH#), but with extra (acidic) #H#. Result slightly alkalinic (#pH~~8.5#)

#Ca_3(PO_4)_2# hardly soluable. Result: near neutral

#NH_4Cl# strong acid (#HCl#), weak base (#NH_4OH#)
Result: acidic (but not very much so -- we eat it!)

#CH_3COOK# (potassium acetate) weak acid, strong base (#KOH#)
Result: alkalic (but not very)

One more example:
#Na_2CO_3# (washing soda) is very alkalinic (why?).