Question

Rank the following 0.10 M solutions in order of increasing pH (lowest pH to highest pH):HCl HF NaCl HOClRank the following 0.10 M solutions in order of increasing pH: HC2H3O2 NaCl NH3 HCl KOH

Answer 1

The pH of a solution determines its acidity or basicity. The order of increasing pH among the given solutions is HCl, HOCl, HF, NaCl.

Step-by-step explanation:

The pH of a solution is a measure of its acidity or basicity. A lower pH value indicates a more acidic solution, while a higher pH value indicates a more basic solution. Based on the given information and the pH scale, we can rank the solutions as follows:

1. HCl (hydrochloric acid) - The strongest acid among the given solutions, it has the lowest pH value.
2. HOCl (hypochlorous acid) - Considered a weak acid, it has a slightly higher pH value than HCl.
3. HF (hydrofluoric acid) - Another weak acid, its pH is higher than HOCl.
4. NaCl (sodium chloride) - A neutral salt, it does not significantly affect the pH of a solution.

Therefore, the correct order of increasing pH would be: HCl, HOCl, HF, NaCl.

Answer 2

1) The ranked solutions from the lowest pH to the highest pH are:

HCl < HF < HClO < NaCl

2) The ranked solutions from the lowest pH to the highest pH are:

HCl < CH₃COOH < NaCl < NH₃ < KOH

Step-by-step explanation:

1) HCl is a strong acid because the concentration of the undissociated species HCl is too low to be measured. A 0.1 M solution of HCl is pH=1

pH=-log[H₃O⁺]=-log[0.1]=1

HF and HClO are weak acids because they partially dissociates when they are dissolved in a solvent.

HF pKa =3.17 ⇒ Ka=
`10^(-3.17)`=6.761×10⁻⁴

pH=
`-log[√(c*Ka) ]`= -log[√(0.1×6.761×10⁻⁴)]=2.1

HClO pKa=7.49 ⇒ Ka=
`10^(-7.49)`=3.236×10⁻⁸

pH=
`-log[√(c*Ka) ]`= -log[√(0.1×3.236×10⁻⁸)]=4.2

NaCl is a neutral salt. The pH of the solution is 7.

`pH_(HCl)=1 < pH_(HF)=2.1 < pH_(HClO)=4.2 < pH_(NaCl)=7`

HCl < HF < HClO < NaCl

2) HCl is a strong acid because the concentration of the undissociated species HCl is too low to be measured. A 0.1 M solution of HCl is pH=1

KOH is a strong base because the concentration of the undissociated species KOH is too low to be measured. A 0.1 M solution of KOH is pOH=1 ⇒ pH= 14 - pOH = 13

CH₃COOH (acetic acid) is a weak acid whose pKa=4.76

Ka=
`10^(-4.76)`=1.738×10⁻⁵

pH=
`-log[√(c*Ka) ]`= -log[√(0.1×1.738×10⁻⁵)]=2.88

NH₃ is a weak base whose pKb=5 ⇒ ⇔Kb=1×10⁻⁵

NH₃ + H₂O ⇔ NH₄⁺ + OH⁻

[OH⁻]=
`√(c*Kb)`= 1×10⁻³

pOH=-log[1×10⁻³]=3

pH=14-pOH= 11

Hence, the rank should be:

`pH_(HCl)=1 < pH_{CH_(3)COOH}=2.88 < pH_(NaCl)=7 < pH_(NH_3)=11 < pH_(KOH)=13`

HCl < CH₃COOH < NaCl < NH₃ < KOH