精英家教网 > 初中化学 > 题目详情

中考复习阶段,某同学梳理了以下知识:①利用金属的化学性质可以区别不同金属的活动性强弱;②酸、碱中一定含有氢元素、盐中一定含有金属元素;③能使酸碱指示剂变色的溶液一定是酸溶液或碱溶液;④燃烧需要同时满足三个条件,故破坏其中一个条件就可以灭火;⑤微量元素是人体健康必不可少的,但补充微量元素也要适可而止;⑥二氧化碳能灭火是因为不能燃烧也不能支持燃烧且密度比空气大,而用水灭火是因为可降低可燃物的着火点。其中你认为合理的是:                   (     )

A.①④⑤           B.①③⑥          C.②⑤⑥            D.②④⑤

练习册系列答案
相关习题

科目:初中化学 来源: 题型:


烟草也是毒品,右图是一幅关于它的危害的漫画。请就人们的健康生活提出两条建议,并用化学知识说明理由:

①________________________________________________________________________;

②________________________________________________________________________。

查看答案和解析>>

科目:初中化学 来源: 题型:


下列关于硝酸铵(NH4NO3)的说法,不正确的是

A.NH4NO3是一种常见的氮肥

B.NH4NO3中含2种不同的原子团

C.NH4NO3中各元素的质量比为1:4:1:3

 


查看答案和解析>>

科目:初中化学 来源: 题型:


某化学兴趣小组同学用Na2CO3溶液和浓HCl来研究简易灭火器的反应原理时,对废液的成分进行探究。

【推理假设】  废液的成分中一定有               ,可能有Na2CO3或盐酸.

【实验探究】  确定废液成分中是否含有Na2CO3或盐酸

     请你协助兴趣小组的同学完成实验探究,并完成实验报告。

实验步骤

现象

结论

该废液中一定没有盐酸                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      

该废液中一定含有Na2CO3

查看答案和解析>>

科目:初中化学 来源: 题型:


 根据下图的有关信息判断,下列说法正确的是                             (     )

A.镁离子(Mg2+)核内有12个质子   

B.镁的相对原子质量为24.31g

    C.在化学反应中,氯原子容易失去1个电子

D.镁离子(Mg2+)与氯离子(Cl)的最外层

电子数不相等

查看答案和解析>>

科目:初中化学 来源: 题型:


写出下列反应的化学方程式,并注明基本反应类型

⑴镁条在空气中燃烧做照明弹                           ;属于(     )反应

⑵硫酸厂的废硫酸,可用熟石灰中和:                     ;属于(     )反应

⑶二氧化氯(ClO2)是一种新型的自来水消毒剂,工业上用氯气和亚氯酸钠(NaClO2

     生产二氧化氯(ClO2),同时生成一种生活中常见的盐                           

查看答案和解析>>

科目:初中化学 来源: 题型:


下列实验现象描述正确的是                                      

A.硫在氧气中燃烧发出淡蓝色火焰             B.硝酸铵溶于水时溶液温度升高

C.浓盐酸打开瓶盖,瓶口有白雾出现           D.氯化铵加熟石灰研磨有氨气产生

                                                                     

查看答案和解析>>

科目:初中化学 来源: 题型:


下列生活中常见的变化中属于化学变化的是

A.榨取果汁         B.雕刻玉器         C.燃放烟花            D.干冰升华

查看答案和解析>>

科目:初中化学 来源: 题型:


根据下图中信息回答下列问题。

(1)下图中三种碱溶于水时解离出的阴离子全部是________。

(2)由上图可推测出,这三种碱具有相似的化学性质。请你写出氢氧化钾(KOH)溶液与三氧化硫(SO3)反应的化学方程式:________________________,石灰水与二氧化硫反应的化学方程式:

________________________________________________________________________。

查看答案和解析>>

同步练习册答案