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A laboratory shelf holds ten nitrogen-containing or related compounds: aniline, hydrazine, urea…
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A laboratory shelf holds ten nitrogen-containing or related compounds: aniline, hydrazine, urea, hydroxylamine hydrochloride, benzenediazonium chloride, nitrobenzene, glycine, glucose, acetamide and pyridine. A student fuses a sample of each with sodium and tests the extract with iron(II) sulphate and acid. A compound gives Prussian blue only if it has both carbon and nitrogen, and its nitrogen is not lost as nitrogen gas on heating. Hydrazine and hydroxylamine have no carbon. A diazonium salt loses its nitrogen as gas. Count the compounds in each group.
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Step 1. No carbon. Hydrazine, , and hydroxylamine hydrochloride, , hold nitrogen but no carbon: 2. Cyanide cannot form.
Step 2. Nitrogen lost. Benzenediazonium chloride loses its nitrogen as gas when it is heated: 1.
Step 3. No nitrogen. Glucose has no nitrogen: 1.
Step 4. Positive. The others are aniline, urea, nitrobenzene, glycine, acetamide and pyridine: 6.
Answer: 6 give Prussian blue and 4 do not (). Two have nitrogen but no carbon, and one loses nitrogen as gas.
Check. , the number of compounds.
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