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Normality Equation:
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Normality (N) is a measure of concentration equal to the gram equivalent weight per liter of solution. For NaOH, the equivalent weight is equal to its molecular weight (40 g/mol) because each NaOH molecule provides one hydroxide ion (OH⁻).
The calculator uses the normality equation:
Where:
Explanation: The equation calculates how many equivalents of NaOH are present per liter of solution.
Details: Normality is particularly important in acid-base chemistry as it directly relates to the reactive capacity of a solution. It's crucial for titration calculations and preparing standard solutions.
Tips: Enter the mass of NaOH in grams and the volume of solution in liters. Both values must be positive numbers. For CO2 calculations, remember that each CO2 molecule can react with two OH⁻ ions, changing the equivalent weight.
Q1: What's the difference between molarity and normality?
A: Molarity is moles per liter, while normality is equivalents per liter. For NaOH, they are the same, but for compounds like H₂SO₄, normality is twice the molarity.
Q2: How does this apply to CO2?
A: For CO2, the equivalent weight is half its molecular weight (22 g/equiv) because each CO2 can react with two OH⁻ ions in neutralization reactions.
Q3: Why use normality instead of molarity?
A: Normality is more convenient for acid-base and redox reactions where the number of reactive sites matters more than the simple molecular count.
Q4: What's a typical normality for NaOH solutions?
A: Common lab concentrations range from 0.1N to 1N, with 1N NaOH containing 40g NaOH per liter of solution.
Q5: How should NaOH solutions be stored?
A: In airtight containers to prevent absorption of CO2 from air, which would change the normality over time.