Question

容积为2L的烧瓶，在压强为时．用塞子塞住，此时温度为27℃，当把它加热到127℃时，塞子被打开了，稍过一会儿．重新把盖子塞好．停止加热并使它逐渐降温到27℃。

求：（1）塞子打开前的最大压强。（2）27℃时剩余空气的压强。

Answer

（1）（2）

【解析】塞子打开前，瓶内气体的状态变化为等容变化。塞子打开后，瓶内有部分气体会逸出，此后应选择瓶中剩余气体为研究对象，再利用查理定律求解。

（1）塞子打开前：选瓶中气体为研究对象，

初态：[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/ae3a1bb2506640e4bf6122ed1d58c3f8.png]，[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/c14f8021c6de44eea15b8701affb50ff.png]

末态：[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/640518e882114035b8cfe31c3bbff1c7.png]，[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/5ca2b97a4c894e77a4bdba90e3af415c.png]

由查理定律可得：[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/e3779df4ed6e4a349cd8e7ea54fb36bf.png]

（2）塞子塞紧后，选瓶中剩余气体为研究对象。

初态：[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/a77b1d5cd23f4b9e9c39dba9e23e49cc.png]，[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/2690b71be4bf43b192659fa0e9ceff92.png]

末态：[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/a6c6f9f7b8fb4eaeb38dc3433c1dd7cf.png]，[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/efaed611fd6e4585b19184cc8405033f.png]T2′

由查理定律可得：[Failed to download image : http://qbm-images.oss-cn-hangzhou.aliyuncs.com/QBM/2011/5/6/1575112499609600/1575112537858048/EXPLANATION/d7d60a37b1b9455ca48bc0cc9d4657f9.png]