合成氨工业的原料气H₂，可用天然气制取，其生产流程如图：

（1）写出反应I的反应方程式：____ 该反应的平衡常数表达式为：____ 　；

（2）转化炉中反应为：CO（g）+H₂O（g）⇌CO₂（g）+H₂（g），其平衡常数与温度关系如表：

该反应为：　放热　反应（填“吸热”或“放热”）．

（3）合成氨反应原理为：N₂（g）+3H₂（g）⇌2NH₃（g）△H=﹣92.4KJ/mol

回答下列问题：

①工业合成氨原料氮气制备方法是____ 

②在一定温度下，将1molN₂和3molH₂充入一容积不变的密闭容时器中进行合成反应，达到平衡时，容器的压强为起始的$\frac{4}{5}$，平衡状态记为S₀，则平衡时容器内NH₃的体积分数为____ ；若保持温度不变，开始时向容器加入a mol N₂，b mol H₂，c mol NH₃，要使反应始终向逆反应方向进行，且达到平衡后向各物质的理与原平衡S₀完全相同，则起始时c的取值范围应是____ ．

阅读理解

You Can Make a Windsock(风筒)

    Have you ever seen a windsock blowing in the wind? Well, you can make one of your own! This is a fun project that you can do with things you may have. You just need to follow a few easy steps.

You will need:

●one piece of heavy colored paper   ●five ribbons

●strong tape       ●a string

●a pencil

What to do:

Step 1: Draw pictures on the paper. You can write your name on it. Do anything that will make it special to you.

    Step 2: Make the paper into the shape of a tube. Hold one of the shorter edges(边缘) over the other. Then make them together with the tape at each end and in the middle.

Step 3: Use a pencil to make a hole into both sides of the tube. The holes should be only on one end of the tube. Pull the string through both holes. Then tie the ends of the string together.

    Step 4: Now make five holes around the top of the other end of the tube.Put a ribbon through each of the holes. Tie a knot in the ends.

    Make sure the knots are bigger than the holes.

    Now your windsock is ready to use, but how does it work? The shape of the tube plays an important part. Wind blows through the tube and makes it fly and dance around. Hold the windsock up in the air by its string and run around. It will fly behind you. You can also hang it outside and watch it dance around on its own!