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.

21a. Calculate the percentage by mass of nitrogen in urea to two decimal places using the data in the appendix. [1 marks]