0.8 g of an organic compound was analysed by Kjeldahl's method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be 42%, then mL of 1M would have been neutra

Question

0.8 g of an organic compound was analysed by Kjeldahl's method for the estimation of nitrogen. If the percentage of nitrogen in the compound was found to be 42%, then  mL of 1M  would have been neutralized by the ammonia evolved during the analysis.

Canvas Classes · Accepted Answer

Step 1: Set Up the Kjeldahl Calculation in Reverse

Given:
- Mass of compound = 0.8 g
- %N = 42%
- Acid used: 1M 
- Find: Volume of  (mL)

Step 2: Calculate Mass and Moles of Nitrogen

Step 3: Calculate Moles of NH₃ Evolved

Each N atom gives one  molecule:

Step 4: Calculate Volume of H₂SO₄ Neutralised

is diprotic:

For 1M :

Answer: 12 mL

Verification using Kjeldahl formula:

Key Points to Remember:
- Reverse Kjeldahl: given %N, find volume of acid
-  normality = 2 × molarity (di

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