第十五届天原杯赛第二大题为填空题,包括7道小题(16、17、18、19、20、21、22题,见本期57、58面),主要考查元素化合物知识,并且在实验、计算、应用、综合中考查元素化合物知识。 16题是一道概念型计算和生活应用结合的题目。羟基磷酸钙中钙元素的质量分数: (40×5)/(502)×100％=39.8％成人每天需0.6g钙,来自牛奶的钙为0.6g×90％=0.54g,而某乳业公司生产的盒装纯牛奶每盒 The second title of the fifteenth Tianyuan Cup is the blank-filling question, which includes 7 questions (16, 17, 18, 19, 20, 21, and 22 questions, see the 57 and 58 questions in this issue). , and examine elemental compound knowledge in experiments, calculations, applications, and synthesis. Question 16 is a combination of conceptual computing and life applications. The mass fraction of calcium in calcium hydroxyphosphate: (40 × 5) / (502) × 100% = 39.8% of adults need 0.6g of calcium per day, milk from milk is 0.6g × 90% = 0.54g, and a dairy company Boxed pure milk produced per box