Question

下表中列出了一些物質(zhì)的熔點和沸點（1標(biāo)準(zhǔn)大氣圧下），根據(jù)表中數(shù)據(jù)回答下列問題：

物質(zhì)	熔點（℃）	沸點（℃）
水	0	100
萘	80	210
水銀	-39	357
酒精	-117	78
氮	-210	-196
氧	-268	-183

（1）表中所列物質(zhì)在常溫下屬于固態(tài)的是________；氧在-145℃時所處的狀態(tài)是______
（2）要探究萘的熔化和沸騰過程中溫度的變化，應(yīng)選_______作溫度計的測量物質(zhì)。
（3）如果在1標(biāo)準(zhǔn)大氣壓下用降溫的辦法從空氣中提取氧和氮，那么溫度下降時首先液化被分離出來的是                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  （4）1標(biāo)準(zhǔn)大氣圧下，當(dāng)溫度為0℃時，水的狀態(tài)（  ）
A．一定是固態(tài)    　       B．一定是液態(tài)    　 
C．一定是固液共存態(tài)      　D．以上三種狀態(tài)都有可能

Answer 1

（1）萘 氣態(tài) （2）水銀 （3）氧  （4）D

試題分析：（1）溫度低于物質(zhì)的熔點該物質(zhì)是固態(tài)，常溫低于80oC，萘是固態(tài)；-145℃高于氧的沸點-183^oC，氧處于氣態(tài)；（2）萘的熔點是80^oC，沸點是210^oC，應(yīng)選水銀溫度計。（3）因為氧的沸點比氮高，采用降溫法，溫度首先低于氧的沸點，氧氣先液化（如采用升溫法則相反）被首先分離出來。（4）0^oC時水的狀態(tài)可能是固態(tài)（冰），也可能是液態(tài)（水），當(dāng)然可能是固液共存（冰水混合物）狀態(tài)。注意：是指水的狀態(tài)，而不是問水是否結(jié)冰。