1. What is Normality?

Normality (N) is a measure of concentration equal to the gram equivalent weight per liter of solution. For NaOH solutions, normality is equal to molarity since NaOH has one reactive hydroxide group per molecule.

2. How Does the Calculator Work?

The calculator uses the normality equation:

Where:

• 40 — Molecular weight of NaOH (g/mol)
• Mass — Mass of NaOH in grams
• Volume — Total volume of solution in liters

Explanation: The equation calculates how many equivalents of NaOH are present per liter of solution.

3. Importance of Normality Calculation

Details: Normality is particularly important in acid-base chemistry as it accounts for the reactive capacity of a solution. It's essential for preparing standard solutions and titration experiments.

4. Using the Calculator

Tips: Enter the mass of NaOH in grams and the total volume of solution in liters. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is 40 used in the calculation?
A: 40 g/mol is the molecular weight of NaOH (Na=23, O=16, H=1). Since NaOH has one reactive group, its equivalent weight equals its molecular weight.

Q2: What's the difference between normality and molarity?
A: Molarity is moles per liter, while normality is equivalents per liter. For NaOH they are equal, but for compounds like H₂SO₄, normality is twice the molarity.

Q3: How should NaOH be measured for accurate results?
A: Use an analytical balance to measure NaOH precisely. Solid NaOH is hygroscopic, so it should be weighed quickly and stored in airtight containers.

Q4: Does temperature affect normality?
A: Temperature affects solution volume slightly, but for most purposes at constant temperature, normality remains stable.

Q5: How should NaOH solutions be stored?
A: Store in plastic or glass bottles with tight lids to prevent absorption of CO₂ from air which would reduce the solution's alkalinity over time.