Calculate the equivalent weight of NaOH in the following reaction:

• 3Br₂ + 6NaOH → 5NaBr + NaBrO₃

To find the equivalent weight of sodium hydroxide (NaOH) in the given reaction, we first need to understand the concept of equivalent weight. The equivalent weight of a substance is calculated by dividing its molar mass by the number of moles of reactive species it provides in a reaction.

Step 1: Determine the Molar Mass of NaOH

The molar mass of NaOH can be calculated as follows:

• Sodium (Na): 23 g/mol
• Oxygen (O): 16 g/mol
• Hydrogen (H): 1 g/mol

Adding these together gives:

Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol

Step 2: Identify the Role of NaOH in the Reaction

In the reaction:

3Br₂ + 6NaOH → 5NaBr + NaBrO₃

Each molecule of NaOH provides one hydroxide ion (OH^-), which reacts with bromine (Br₂). Since 6 moles of NaOH are used to react with 3 moles of Br₂, we can see that:

6 moles of NaOH yield 6 equivalents of OH^-.

Step 3: Calculate the Equivalent Weight

Now, we can find the equivalent weight of NaOH:

Equivalent weight = Molar mass / Number of equivalents

Here, the number of equivalents is 6 (from the 6 moles of NaOH). Thus:

Equivalent weight of NaOH = 40 g/mol / 6 = 6.67 g/equiv

Final Result

The equivalent weight of NaOH in this reaction is approximately 6.67 grams per equivalent.