1. What is Normality?

Normality (N) is a measure of concentration equal to the gram equivalent weight per liter of solution. For acid-base reactions, it represents the number of H+ or OH- ions a compound can donate or accept per liter.

2. How Does the Calculator Work?

The calculator uses the normality equation:

Where:

• \( \text{mass NaOH} \) — Mass of sodium hydroxide in grams
• \( 40 \) — Molar mass of NaOH (g/mol)
• \( V \) — Volume of solution in liters (converted from mL input)
• \( 2 \) — Equivalent factor for H2SO4 (diprotic acid)

Explanation: The equation calculates how many equivalents of base (NaOH) are present per liter of solution, adjusted for the diprotic nature of sulfuric acid.

3. Importance of Normality Calculation

Details: Normality is crucial in acid-base titrations as it directly relates the volumes of acid and base that will neutralize each other. It's particularly important when dealing with polyprotic acids like H2SO4.

4. Using the Calculator

Tips: Enter the mass of NaOH in grams and the total volume of solution in mL. Ensure all values are positive numbers for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: Why multiply by 2 in the calculation?
A: The factor of 2 accounts for H2SO4 being a diprotic acid (can donate 2 H+ ions), so each mole of H2SO4 can neutralize 2 moles of NaOH.

Q2: What's the difference between molarity and normality?
A: Molarity is moles per liter, while normality is equivalents per liter. For monoprotic acids/bases they're equal, but differ for polyprotic species.

Q3: Why use 40 as the molar mass?
A: 40 g/mol is the molar mass of NaOH (Na=23, O=16, H=1). This converts grams to moles for the calculation.

Q4: Can I use this for other acid-base pairs?
A: This specific calculator is designed for NaOH-H2SO4. Other pairs may require different equivalent factors.

Q5: How precise should my measurements be?
A: For best results, measure mass to at least 3 decimal places and volume to 1 decimal place when preparing solutions.