題組內容

Part 2. Short Answer [80 marks]

Using Mandarin to answer the short questions is allowed except question 32 and 33.

21. Urea, (H₂N)₂CO, is excreted by mammals and can be used as a fertilizer.

21c. Urea can be made by reacting potassium cyanate, KNCO, with ammonium chloride, NH₄Cl. KNCO(aq) + NH₄Cl(aq) → (H₂N)₂CO(aq) + KCl(aq)
Determine the maximum mass of urea that could be formed from 50.0 cm of 0.100 mol dm^–3potassium cyanate solution. [1 marks]