Answer: [tex]NH_4NO_3[/tex]
Explanation: Acidic salts are those which are formed by combination of strong acid and a weak base and have acidic pH of less than 7.
Basic salts are those which are formed by combination of weak acid and a strong base and have basic pH of more than 7.
Neutral salts are those which are formed by combination of weak acid and a weak base or by combination of strong acid and a strong base and have neutral pH equal to 7.
1) [tex]KBr[/tex] is a neutral salt formed by combination of strong acid [tex]HBr[/tex] and a strong base [tex]KOH[/tex].
2) [tex]HCOOK[/tex] is a basic salt formed by combination of weak acid [tex]HCOOH[/tex] and a strong base [tex]KOH[/tex].
3) [tex]CaSO_4[/tex] is a neutral salt formed by combination of strong acid [tex]H_2SO_4[/tex] and a strong base [tex]Ca(OH)_2[/tex].
4) [tex]NH_4NO_3[/tex] is an acidic salt formed by combination of strong acid [tex]HNO_3[/tex] and a weak base [tex]NH_4OH[/tex].
