Calculate The Ph Of A 0.59 M Koh Solution Chegg

Use this premium chemistry calculator to solve the pH of potassium hydroxide solutions instantly. By default, it is set to the exact problem “calculate the pH of a 0.59 M KOH solution chegg” and assumes complete dissociation at 25 C, which is the standard general chemistry approach.

Expert Guide: How to Calculate the pH of a 0.59 M KOH Solution

If you are searching for how to calculate the pH of a 0.59 M KOH solution, the chemistry is straightforward once you know the behavior of strong bases in water. Potassium hydroxide, written as KOH, is a classic strong base in introductory chemistry. That means it dissociates almost completely in aqueous solution:

KOH(aq) → K⁺(aq) + OH^–(aq)

Because each formula unit of KOH produces one hydroxide ion, a 0.59 M KOH solution gives an hydroxide concentration of approximately [OH^–] = 0.59 M. Once you know that, the next step is to compute the pOH using the logarithmic relationship:

pOH = -log[OH^–]

Plugging in the value:

pOH = -log(0.59) ≈ 0.229

At 25 C, pH and pOH are related by:

pH + pOH = 14.00

Therefore:

pH = 14.00 – 0.229 = 13.771

So, the pH of a 0.59 M KOH solution is about 13.77 at 25 C. That is the answer most general chemistry courses, homework systems, and study platforms expect.

Final answer at 25 C: pH ≈ 13.77 and pOH ≈ 0.23.

Why KOH Is Treated as a Strong Base

KOH is an alkali metal hydroxide. In first year chemistry, alkali metal hydroxides such as LiOH, NaOH, and KOH are categorized as strong bases because they dissociate extensively in water. In practical homework calculations, this means you do not need an equilibrium ICE table or a base dissociation constant expression for KOH. You simply treat the hydroxide concentration as equal to the initial molarity of the dissolved base, provided the stoichiometric coefficient for OH^– is 1.

• KOH is a strong electrolyte in water.
• One mole of KOH yields one mole of OH^–.
• For 0.59 M KOH, [OH^–] = 0.59 M.
• Then compute pOH, and use pH = 14.00 – pOH at 25 C.

Step by Step Method for This Exact Problem

1. Identify the compound as a strong base: KOH.
2. Write the dissociation: KOH → K⁺ + OH^–.
3. Set hydroxide concentration equal to the base concentration: [OH^–] = 0.59 M.
4. Compute pOH: pOH = -log(0.59) ≈ 0.229.
5. Compute pH at 25 C: pH = 14.00 – 0.229 = 13.771.
6. Round according to the expected precision, usually pH ≈ 13.77.

Common Student Mistakes

Even though this is a relatively simple strong base problem, students often lose points for very avoidable reasons. If you want the correct answer every time, watch out for these frequent errors:

• Confusing pH and pOH: For a base, you typically find pOH first because the direct ion given is OH^–.
• Using the wrong concentration: For KOH, use the KOH molarity directly as the OH^– molarity.
• Forgetting the logarithm sign: pOH is negative log, not just log.
• Using 14 without temperature context: The shortcut pH + pOH = 14.00 is strictly valid at 25 C.
• Incorrect rounding: pOH is about 0.229, not 0.23 before carrying to final precision.

Comparison Table: Strong Bases and Hydroxide Stoichiometry

One reason this problem is easy is that KOH contributes exactly one OH^– per formula unit. The table below compares several common bases and the number of hydroxide ions each can contribute in ideal stoichiometric treatment.

Base	Type	OH- Released per Formula Unit	If Solution Is 0.59 M, Ideal [OH-]
KOH	Strong base	1	0.59 M
NaOH	Strong base	1	0.59 M
Ba(OH)2	Strong base	2	1.18 M
Al(OH)3	Weakly soluble and amphoteric context matters	3 by formula, but not treated the same in simple dissociation problems	Not handled by the same simple assumption

What the Number 13.77 Means Chemically

A pH of about 13.77 indicates a highly basic solution. On the pH scale used at 25 C, values above 7 are basic, and values approaching 14 are strongly basic. Since 0.59 M KOH contains a large hydroxide concentration, the pOH is small, which forces the pH to be very high.

This is also a good example of why logarithms matter in chemistry. A pH difference of 1 unit is not a small linear change. Instead, each pH unit corresponds to a tenfold change in hydrogen ion concentration. Because 0.59 M is a relatively concentrated base, its pH lands near the upper end of the common aqueous pH scale at room temperature.

Reference Table: pKw Changes With Temperature

Many homework sets assume 25 C and use pH + pOH = 14.00. In more advanced settings, the ion product of water changes with temperature, so pKw shifts too. The values below are commonly cited approximations in chemistry instruction.

Temperature	Approximate pKw	If [OH-] = 0.59 M, pOH	Calculated pH
20 C	14.17	0.229	13.941
25 C	14.00	0.229	13.771
37 C	13.60	0.229	13.371
50 C	13.26	0.229	13.031

How This Problem Is Usually Solved in Class

In a standard general chemistry course, instructors want you to recognize categories of acids and bases quickly. Strong acids and strong bases are special because they simplify concentration calculations. Here, the phrase “0.59 M KOH” should instantly signal that the hydroxide concentration is known directly. No Ka or Kb values are needed. No equilibrium table is necessary. No approximation such as x is small is required.

The method is much simpler than it would be for a weak base like ammonia, where you must use Kb and solve for equilibrium hydroxide concentration. For KOH, the concentration itself is enough. This is exactly why the problem appears often in online homework systems, exam reviews, and textbook chapter sets. It tests whether you can distinguish between strong electrolyte behavior and weak base equilibrium behavior.

Short Answer Format for Homework

If you need a concise answer you can model after in your own work, here is a clean format:

1. KOH is a strong base, so it dissociates completely.
2. [OH^–] = 0.59 M.
3. pOH = -log(0.59) = 0.229.
4. pH = 14.00 – 0.229 = 13.771.
5. Answer: pH = 13.77.

Why the Calculator Above Is Useful

The calculator on this page does more than give a single answer. It lets you explore how pH changes if you alter concentration, change the hydroxide stoichiometry, or adjust the pKw assumption for a different temperature. That matters because many learners memorize formulas without understanding where the answer comes from. Interactive tools help you see that:

• Increasing concentration raises [OH^–] and usually increases pH.
• Bases that produce more than one OH^– per unit can change pH more dramatically.
• The relationship between concentration and pH is logarithmic, not linear.

Authoritative Chemistry References

If you want to confirm the strong base framework and pH definitions from trusted educational or government sources, these references are excellent starting points:

• LibreTexts Chemistry for broad educational coverage of acids, bases, pH, and strong electrolyte behavior.
• U.S. Environmental Protection Agency for pH fundamentals and water chemistry context.
• National Institute of Standards and Technology for authoritative scientific data and standards related to chemical measurements.

Final Takeaway

To calculate the pH of a 0.59 M KOH solution, treat KOH as a strong base that fully dissociates. That gives [OH^–] = 0.59 M. Compute pOH with the negative logarithm, then convert to pH using the 25 C relationship pH + pOH = 14.00. The result is:

pH ≈ 13.77

If your instructor expects three decimal places, report 13.771. If the class uses two decimal places, 13.77 is ideal. That is the correct chemistry answer for the common textbook and homework interpretation of this problem.