Chemistry (acid and bases)

definition of salts: the hydrogen ion of an acid is replaced by metal/ ammonium ion
therefore, carbonates are salts; as they are the product from carbonic acid (H2CO3)

Bases are generally compounds that can neutralize an amount of acids. carbonates are bases, although they don't contain OH− groups

if the base is soluble in water, it may contaminate the final product if the amount is not controlled carefully (e.g. by titration)
for example we want to prepare CaCl2(aq)
there are two methods:
1. CaCO3 + HCl
2. Ca(HCO3)2 + HCl

in first method, CaCO3 is insoluble. when we add excess CaCO3 in HCl until reaction is completed. the unreacted CaCO3 will remain undissolved in the solution. we can simply filter it away to obtain the clear filtrate (CaCl2 aq)

in second method, Ca(HCO3)2 is soluble. when we add excess Ca(HCO3)2 in HCl until reaction is completed. the unreacted Ca(HCO3)2 remain in the solution in aq form. therefore, the CaCl2 is contaminated by Ca(HCO3)2.

Acid-Base definitions:
Arrhenius?
Bronsted?
Lewis?
Lux-Flood?