Problem: Arrange the following 0.10 M solutions in order of most acidic to most basic.             KOH, KNO 3, KCN, NH4Cl, HCl

🤓 Based on our data, we think this question is relevant for Professor Bell's class at PSU.

FREE Expert Solution

We’re being asked to identify which among the given acids is a weak acid.


Weak acids are weak electrolytes that don’t completely ionize but instead reach a state of equilibrium. 


However, it’s easier to identify strong acids than familiarize yourself with all the weak acids (since the common strong acids have rules and are relatively fewer).


Strong acids are considered strong electrolytes. They completely dissociate into ions when dissolved in water.

Strong binary acids – paired with a highly electronegative atom

Strong binary acids are:              HCl, HBr, and HI

Strong oxyacids (or oxoacids) - have 2 or more oxygens than hydrogens

Oxyacids → possess H+ ion, connected to nonmetal and oxygen

Common strong oxyacids are:                  HNO3, HClO3, HClO4, H2SO4

Exceptions to the rule are:                            Oxalic acid (H2C2O4and Iodic acid (HIO3)

▪ both have 2 more O than H but are weak acids because carbon and iodine have low electronegativity


Bases: 

  • Any Group 1A metal when combined with OH , H , O2– or NH2 makes a STRONG BASE.
  • Group 2A metals, from Ca2+ to Ba2+, when combined with OH , H , O2– or NH2 makes a STRONG BASE. 
  • Amines are compounds with only nitrogen or hydrogen (i,e. NH3) or with carbon, nitrogen and hydrogen (i,e. CH3NH2).



Let’s take a look at each of the given compounds:


 KOH, KNO3, KCN, NH4Cl, HCl

A)  KOH

  • Group 1A metal when combined with OH
  • Strong Base


B)  KNO 3

NO3- →  Conjugate base of strong acid
Neutral salt


C)  KCN

NO3- →  Conjugate base of weak acid
Basic salt


D)  NH4Cl

NH4+ →  Conjugate acid of weak base
Acidic salt


E)  HCl

one of the strong binary acids
Strong Acid


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Problem Details

Arrange the following 0.10 M solutions in order of most acidic to most basic.

             KOH, KNO 3, KCN, NH4Cl, HCl

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Identifying Acids and Bases concept. You can view video lessons to learn Identifying Acids and Bases. Or if you need more Identifying Acids and Bases practice, you can also practice Identifying Acids and Bases practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Bell's class at PSU.

What textbook is this problem found in?

Our data indicates that this problem or a close variation was asked in Chemistry: An Atoms First Approach - Zumdahl 2nd Edition. You can also practice Chemistry: An Atoms First Approach - Zumdahl 2nd Edition practice problems.