Question

A. What was the pH change when HCI was added to tap water?

b. Is HCI an acid, base, or neutral?

c. What was the pH change when NaOH was added to tap water?

d. is NAOH an acid, base, or neutral?

Answer 1

See below.

Step-by-step explanation:

a. The pH would decrease.

b. An acid.

c. The pH would increase.

d. A base. More accurately an alkali ( which is a soluble base).

Answer 2

A)

Solution:

Adding a strong acid such as HCl to water results in the release of H+ ions.

Arrhenius Theory: An acid is a substance which produces one or more hydrogen ions, (H+) in aqueous solution.

Examples:

`HCl(aq)>(aq)H^+Cl^-(aq)`

(H+) from the acid binds to neutral water molecules to form
`H_3O^+` raising the concentration of H+.

The resulting large concentration of (H+) makes the solution more acidic and leads to a dramatic drop in the pH.

B)

Solution :

An acid is a substance which produces one or more hydrogen ions, (H+) in aqueous solution.

Examples:

`HCl(aq)>(aq)H^+Cl^-(aq)`

So, HCl is an acid.

C)

Solution :

A Base is a substance which produces one or more hydroxyl ion or hydroxide ion (OH-) in aqueous solution.

Examples :

`KOH(s)> K^+(aq) +OH^-(aq)\\\\Ca(OH)_2(s)>Ca^(2+)(aq)  +2OH^- (aq)\\\\Al(OH)_3(s)> Al^(3+)(aq)+ 3OH^- (aq)`

Please note: (aq) stands for aqueous which means in the presence of water that is, water acts as a solvent

The release of OH- ions makes the solution more basic and this leads to an increase in pH of the solution

D)

Solution:

A Base is a substance which produces one or more hydroxyl ion or hydroxide ion (OH-) in aqueous solution.

Examples

`KOH(s)> K^+(aq) +OH^-(aq)\\\\Ca(OH)_2(s)>Ca^(2+)(aq)  +2OH^- (aq)\\\\Al(OH)_3(s)> Al^(3+)(aq)+ 3OH^- (aq)`

Please note: (aq) stands for aqueous which means in the presence of water that is, water acts as a solvent

So, NaOH is a Base.