**Molarity of 45% Potassium Hydroxide (KOH)**

**Overview:**

- Potassium Hydroxide (KOH) is a clear colourless liquid. A 45% (w/w) concentrated Potassium Hydroxide can be obtained from different suppliers.
- 45% (w/w) Potassium Hydroxide means that 100 grams of Potassium Hydroxide contains 45 grams of KOH.
- The density of 45% (w/w) Potassium Hydroxide is 1.456 g/ml at 25°C that means that weight of the 1 ml of Potassium Hydroxide is 1.456 gram at 25°C.
- Molarity refers to number of moles of the solute present in 1 litre of solution.
- In simple words, 1 mole is equal to atomic weight of the substance. For example, 1 mole of KOH is equal to 56.11 grams of KOH (molecular weight = 56.11).

# Related content

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- Table: Molarity of commercially supplied concentrated acids and bases
- Calculator – Calculate the molarity of concentrated Formic acid (HCOOH)
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- Calculator – Calculate the molarity of concentrated Potassium Hydroxide (KOH)
- Calculator – Calculate the molarity of concentrated Potassium Hydroxide (KOH)

**Calculation procedure:**

**Known values:**

Concentration of Potassium Hydroxide: 45% (% by mass, wt/wt)

**Step 1: Calculate the volume of 100 grams of Potassium Hydroxide.**

**Formula:**

Volume of 100 gram of Potassium Hydroxide : 100/1.456 = 68.6813 ml

Note: 45% (w/w) Potassium Hydroxide means that 100 grams of Potassium Hydroxide contain 45 grams of KOH.

**The volume of 100 grams of Potassium Hydroxide is 68.6813 ml. That means 45 grams of KOH is present in 68.6813 ml of Potassium Hydroxide.**

**Step 2: Calculate how many grams of KOH is present in 1000 ml of Potassium Hydroxide.**

1000 ml of Potassium Hydroxide will contain = 1000 x 45/68.6813 = 655.2 grams of KOH

**1000 ml of Potassium Hydroxide will contain 655.2 grams of KOH**

**Step 3: Calculate number of moles of KOH present in 655.2 grams of KOH.**

655.2 grams will be equal to = 655.2 x 1/56.11 = 11.677 moles

**Therefore, we can say that 1 litre of Potassium Hydroxide contains 11.677 moles or in other words molarity of 45% (w/w) Potassium Hydroxide is equal to 11.677 M.**