Amphiprotic. The preferred term is amphoteric. A compound that is amphoteric can behave as either an acid or a base. These are most commonly explained when using the Bronsted-Lowry theory of acids and bases. Sorry. NONE of these are amphoteric (or amphiprotic). In order to behave as a Bronsted-Lowry acid it must donate a proton. That narrows it down to HCl and HSO4-. In order to behave as a base it must accept a proton. A, D and E can all accept protons. HCl is a strong acid and dissociates to form H+ and Cl-. There is no tendency to gain a proton. HSO4- is a weak acid and can donate a proton, but it won\'t accept a proton to make H2SO4 because H2SO4 is a strong acid and completely dissociates. Even if one of the choices had been HSO3- we would still have a problem. It would be tempting to say that HSO3- could gain a proton to make the weak acid H2SO3. The problem is that H2SO3 does not exist in aqueous solution. It is a fictitious acid, much like H2CO3 which also cannot exist in aqueous solution. The bottom line is that NONE of these are amphoteric. ========= Follow up ========== See! HPV got suckered. Sorry, you can\'t possibly form H2SO4 and OH-. H2SO4 is a strong acid and completely dissociates to form H+ and HSO4-. The H+ will combine with OH- to make water, and you\'re right back where you started. No. HSO4- is NOT amphoteric in aqueous solution. ======= More follow up ========== \"Would it matter about the physical state?\" No. For the substance to gain a proton, it will be in aqueous solution. As soon as HCl interacts with water it will dissociate to form H+ and Cl-. =============================== You may see that HSO4- is listed as an amphoteric substance, but only because whoever wrote that didn\'t think it through. Solution Amphiprotic. The preferred term is amphoteric. A compound that is amphoteric can behave as either an acid or a base. These are most commonly explained when using the Bronsted-Lowry theory of acids and bases. Sorry. NONE of these are amphoteric (or amphiprotic). In order to behave as a Bronsted-Lowry acid it must donate a proton. That narrows it down to HCl and HSO4-. In order to behave as a base it must accept a proton. A, D and E can all accept protons. HCl is a strong acid and dissociates to form H+ and Cl-. There is no tendency to gain a proton. HSO4- is a weak acid and can donate a proton, but it won\'t accept a proton to make H2SO4 because H2SO4 is a strong acid and completely dissociates. Even if one of the choices had been HSO3- we would still have a problem. It would be tempting to say that HSO3- could gain a proton to make the weak acid H2SO3. The problem is that H2SO3 does not exist in aqueous solution. It is a fictitious acid, much like H2CO3 which also cannot exist in aqueous solution. The bottom line is that NONE of these are amphoteric. ========= Follow up ========== See! HPV got suckered. Sorry, you can\'t possibly form H2SO4 and OH-. H2SO4 is a strong acid and completely dissociates to form H+ a.

1. Amphiprotic. The preferred term is amphoteric. A compound that is amphoteric can
behave as either an acid or a base. These are most commonly explained when using the
Bronsted-Lowry theory of acids and bases. Sorry. NONE of these are amphoteric (or
amphiprotic). In order to behave as a Bronsted-Lowry acid it must donate a proton. That
narrows it down to HCl and HSO4-. In order to behave as a base it must accept a proton. A, D
and E can all accept protons. HCl is a strong acid and dissociates to form H+ and Cl-. There is
no tendency to gain a proton. HSO4- is a weak acid and can donate a proton, but it won't accept
a proton to make H2SO4 because H2SO4 is a strong acid and completely dissociates. Even if
one of the choices had been HSO3- we would still have a problem. It would be tempting to say
that HSO3- could gain a proton to make the weak acid H2SO3. The problem is that H2SO3 does
not exist in aqueous solution. It is a fictitious acid, much like H2CO3 which also cannot exist in
aqueous solution. The bottom line is that NONE of these are amphoteric. ========= Follow
up ========== See! HPV got suckered. Sorry, you can't possibly form H2SO4 and OH-.
H2SO4 is a strong acid and completely dissociates to form H+ and HSO4-. The H+ will combine
with OH- to make water, and you're right back where you started. No. HSO4- is NOT
amphoteric in aqueous solution. ======= More follow up ========== "Would it matter
about the physical state?" No. For the substance to gain a proton, it will be in aqueous solution.
As soon as HCl interacts with water it will dissociate to form H+ and Cl-.
=============================== You may see that HSO4- is listed as an amphoteric
substance, but only because whoever wrote that didn't think it through.
Solution
Amphiprotic. The preferred term is amphoteric. A compound that is amphoteric can
behave as either an acid or a base. These are most commonly explained when using the
Bronsted-Lowry theory of acids and bases. Sorry. NONE of these are amphoteric (or
amphiprotic). In order to behave as a Bronsted-Lowry acid it must donate a proton. That
narrows it down to HCl and HSO4-. In order to behave as a base it must accept a proton. A, D
and E can all accept protons. HCl is a strong acid and dissociates to form H+ and Cl-. There is
no tendency to gain a proton. HSO4- is a weak acid and can donate a proton, but it won't accept
a proton to make H2SO4 because H2SO4 is a strong acid and completely dissociates. Even if
one of the choices had been HSO3- we would still have a problem. It would be tempting to say
that HSO3- could gain a proton to make the weak acid H2SO3. The problem is that H2SO3 does
not exist in aqueous solution. It is a fictitious acid, much like H2CO3 which also cannot exist in
aqueous solution. The bottom line is that NONE of these are amphoteric. ========= Follow
up ========== See! HPV got suckered. Sorry, you can't possibly form H2SO4 and OH-.
H2SO4 is a strong acid and completely dissociates to form H+ and HSO4-. The H+ will combine

2. with OH- to make water, and you're right back where you started. No. HSO4- is NOT
amphoteric in aqueous solution. ======= More follow up ========== "Would it matter
about the physical state?" No. For the substance to gain a proton, it will be in aqueous solution.
As soon as HCl interacts with water it will dissociate to form H+ and Cl-.
=============================== You may see that HSO4- is listed as an amphoteric
substance, but only because whoever wrote that didn't think it through.