规矩的重要性:为什么水在100摄氏度时能沸腾

因为在100度时达到了水的沸点,液体达到沸点后会从液态转为另一种形态---气态,所以水以沸腾的形式转为水蒸气了.如果气压低了水还会在小于100度的情况下沸腾,沸点随气压的改变而改变

饱和蒸气压
Saturation vapor pressure

饱和蒸气压指在一个密闭空间内，某种物质在给定的温度下，该物质的液相、气相共存时的气体压力。此时，蒸发/凝结过程达到动态平衡。

通常对水来说温度越高，蒸气压越大。当空气的压强与饱和蒸汽压相等时，对应的温度称为露点，这时空气的相对湿度为100%。此时如果降低温度或者增加空气中水蒸气的含量，就会出现水凝结的现象。水的饱和蒸汽压可以根据Goff-Gratch方程确定。

水的饱和蒸气压
(×102Pa，273.2～313.2K)

--------------------------------------------------------------------------------

温度/K 0.0 0.2 0.4 0.6 0.8
273 － 6.105 6.195 6.286 6.379
274 6.473 6.567 6.663 6.759 6.858
275 6.958 7.058 7.159 7.262 7.366
276 7.473 7.579 7.687 7.797 7.907
277 8.019 8.134 8.249 8.365 8.483
278 8.603 8.723 8.846 8.970 9.095
279 9.222 9.350 9.481 9.611 9.745
280 9.881 10.017 10.155 10.295 10.436
281 10.580 10.726 10.872 11.022 11.172
282 11.324 11.478 11.635 11.792 11.952
283 12.114 12.278 12.443 12.610 12.779
284 12.951 13.124 13.300 13.478 13.658
285 13.839 14.023 14.210 14.397 14.587
286 14.779 14.973 15.171 15.369 15.572
287 15.776 15.981 16.191 16.401 16.615
288 16.831 17.049 17.260 17.493 17.719
289 17.947 18.177 18.410 18.648 18.886
290 19.128 19.372 19.618 19.869 20.121
291 20.377 20.634 20.896 21.160 21.426
292 21.694 21.968 22.245 22.523 22.805
293 23.090 23.378 23.669 23.963 24.261
294 24.561 24.865 25.171 25.482 25.797
295 26.114 26.434 26.758 27.086 27.418
296 27.751 28.088 28.430 28.775 29.124
297 29.478 29.834 30.195 30.560 30.928
298 31.299 31.672 32.049 32.432 32.820
299 33.213 33.609 34.009 34.413 34.820
300 35.232 35.649 36.070 36.496 36.925
301 37.358 37.796 38.237 38.683 39.135
302 39.593 40.054 40.519 40.990 41.466
303 41.945 42.429 42.918 43.411 43.908
304 44.412 44.923 45.439 45.958 46.482
305 47.011 47.547 48.087 48.632 49.184
306 49.740 50.301 50.869 51.441 52.020
307 52.605 53.193 53.788 54.390 54.997
308 55.609 56.229 56.854 57.485 58.122
309 58.766 59.412 60.067 60.727 61.395
310 62.070 62.751 63.437 64.131 64.831
311 65.537 66.251 66.969 67.693 68.425
312 69.166 69.917 70.673 71.434 72.202
313 72.977 73.759 － － －

由此可以看出，当一个大气压时，水在100摄氏度时的饱和蒸气压等于大气压，因此继续吸热便会沸腾。