题干

一定质量分数的硝酸钾溶液可用做无土栽培的营养液.请通过计算回答:

(1)硝酸钾中钾元素、氮元素、氧元素的质量比是  ____ .

(2)某蔬菜基地欲配制500kg溶质质量分数为8%的硝酸钾溶液,需要硝酸钾  ____ kg,水  ____ kg.

(3)已知在150C时硝酸钾的溶解度为25g,则该温度下硝酸钾的饱和溶液中溶质质量与溶液质量的最简整数比为 ____

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答案(点此获取答案解析)

39:14:48,40,460,1:5

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Guilin is my favorite city in China because of its beauty, its waterways, its cafes, and most of all because I met my wife there. It is her hometown and we will both retire there in a few years.

Not only is Guilin a fascinating city, there are many interesting places to visit within a short drive from there. The Ling (sometimes called Lingqu) canal is the oldest canal in the world. It was built about 2,200 years ago and connects two major river systems, the Yangtze (to the east) and the Pearl River.

Longsheng Rice Terraces (龙胜梯田) is another manmade wonder that was built around 650 years ago. I have some photos of both of these places in my China Daily homepage Albums. Gudong Waterfall Park(古东瀑布) is another attraction that is worth visiting. The hike to the top of all these waterfalls isn’t very difficult and if you want, you can take a ride to the bottom on a personal rail car whose speed you can control with a brake.

If you want you can also climb up some of the waterfalls with the help of chains that are placed for the convenience of amateur climbers.

I have only been in Guilin during the winter and spring but my wife tells me it gets pretty hot in the summertime. That’s OK because I grew up in the Midwest of the US where it gets very hot and humid during the summer months. It rarely freezes in the winter and the spring and autumn are pleasant. Guilin receives a lot of rain, especially in late spring and early summer. Because of this there is lush(多汁的) plant life and many large trees in the area. 

Being from California I’m used to having a car to get around. In fact, it’s practically a necessity in California. But in Guilin almost everything is within walking distance and if you need to go further, public buses are available every five minutes on the busy streets and every 10-15 minutes just about everywhere else. There are plenty of taxis too and most trips are only six yuan.

It’s a perfect place to retire.