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题目
题型:不详难度:来源:
如图是“探究某物质熔化和凝固规律”的实验图像,下列说法正确的是(     )
A.该物质凝固点是45℃
B.在BC段,该物质没有吸热所以温度不变
C.在t=2min时,该物质处于固液共存状态
D.EF段物质吸收了热量

答案
A
解析

试题分析:晶体熔化(凝固)过程中继续吸(放)热温度保持熔(凝固)点不变。观察图像,BC段为熔化过程,继续吸热,温度保持45℃不变,时间从3min到5min之间,EF段为凝固过程,放热但温度保持凝固点45℃不变。对照各选项,A正确,B错误,D错误;C错,t=2min时,物质是固态。
核心考点
试题【如图是“探究某物质熔化和凝固规律”的实验图像,下列说法正确的是(     )A.该物质凝固点是45℃B.在BC段,该物质没有吸热所以温度不变C.在t=2min时】;主要考察你对物态变化等知识点的理解。[详细]
举一反三
下表中列出了一些物质的熔点和沸点(1标准大气圧下),根据表中数据回答下列问题:
物质
熔点(℃)
沸点(℃)

0
100

80
210
水银
-39
357
酒精
-117
78

-210
-196

-268
-183
(1)表中所列物质在常温下属于固态的是________;氧在-145℃时所处的状态是______
(2)要探究萘的熔化和沸腾过程中温度的变化,应选_______作温度计的测量物质。
(3)如果在1标准大气压下用降温的办法从空气中提取氧和氮,那么温度下降时首先液化被分离出来的是                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  (4)1标准大气圧下,当温度为0℃时,水的状态(  )
A.一定是固态            B.一定是液态      
C.一定是固液共存态       D.以上三种状态都有可能
题型:不详难度:| 查看答案
用如图(甲)所示的装置做“探究冰的熔化特点”的实验
(1)装有碎冰的烧杯直接放置在空气中,不用酒精灯加热。这样做,不但能使烧杯均匀受热,而且冰的温度升高较_________(选填“快”或“慢”),便于记录各个时刻的温度。为了使烧杯内的冰各部分受热均匀,还需要进行的操作是__________。
(2)实验中,应始终注意观察烧杯中冰的_____      变化,并每隔0.5min记录一次温度计的示数,其中,由图(乙)可读出第1min时温度计的示数是______℃。

(3)根据下表数据,在图(丙)中画出这段时间内冰温度随时间变化的图像。
时间/min
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
......
温度/℃
-8
-6
 
-2
0
0
0
0
0
1
2
状态
固态
固液共存态
固态
(4)由图像可以看出,此实验中冰熔化经历了_______min,冰在熔化过程中温度________(选填“变化”或“不变”)。
题型:不详难度:| 查看答案
现代建筑出现一种新设计,在墙面装饰材料中均匀混入小颗粒球状物,球内充入一种非晶体材料,当温度升高时,球内材料熔化吸热,当温度降低时,球内材料凝固放热,使建筑内温度基本保持不变,从而起到调温的作用。下面四个图象中表示球内材料的凝固图象的是

题型:不详难度:| 查看答案
晶体熔化需要两个条件:一是温度要达到      ,二是需要继续           
题型:不详难度:| 查看答案
如图所示为甲、乙、丙、丁四种物质在加热条件相同的情况下,温度随时间变化的图象,可以看出,这四种物质中,   是非晶体,   两种可能是同种物质。

题型:不详难度:| 查看答案
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