The transformation occurring in Duma's method is given below. Cu y x N z O H y xCO CuO y x N H C 2 7 — JEE Mains Chemistry Past Papers Chemistry Question

💡 Solution & Explanation

# Solution: Finding y in Duma's Method **Step 1: Identify the reaction** In Duma's method, an organic compound containing nitrogen is decomposed over hot copper oxide, producing CO, H₂O, N₂, and excess CuO. **Step 2: Write the balanced equation** The general form is: $$C_xH_yN_zO \cdot CuO → CO + H_2O + N_2 + CuO$$ **Step 3: Apply conservation of atoms** From the given compound C₇HᵧNzO: - Carbon atoms: 7 = number of CO molecules - Nitrogen atoms: z = N₂ molecules (z must be even) - Hydrogen atoms: y = 2 × H₂O molecules **Step 4: Balance hydrogen** Since hydrogen appears only in H₂O on the product side: $$y = 2 × \text{(coefficient of H₂O)}$$ For a typical organic compound with formula C₇HᵧNzO, we need to determine y from standard organic chemistry rules. **Step 5: Use degree of unsaturation or common organic compounds** For C₇HᵧN₁O (assuming z=1, the most common case), applying the formula for degree of unsaturation and considering this is likely a known compound, y = 5 gives aniline derivative or similar structure. Testing: C₇H₅NO would be balanced. **Therefore, the answer is y = 5**