What is dry methylbenzene?

2006-10-23 2:58 am
Which of the following statements concerning a solution of hydrogen chloride in dry methylbenzene is correct?

A.It can conduct electricity
B.Its pH value is smaller than 7
C.When magnesium is added to it, a gas is evolved.
D.When ammonia gas is bubbled into it, a white precipitate is formed.

What is the exact answer? Please reply with explanation.
By the way, what is dry methylbenzene?

回答 (2)

2006-10-23 3:10 am
✔ 最佳答案
the answer should be D
methylbenzene is a organic solvant.
hydrogen chloride in dry methylbenzene means HCl doesn't ionize into H+ and Cl- in the solution because of no water.
so both A and B are incorrect because of no mobile ions and H+
also, because of no water again, HCl cannot apply its acidic property to take reaction with Mg, so no gas is evolved
ammonia gas will react with HCl gas to form NH4Cl which is so called white ppt
參考: me
2006-10-26 6:01 pm
国标编号 32052
CAS号 108-88-3
中文名称 甲基苯
英文名称 methylbenzene;Toluene
别 名 甲苯
分子式 C7H8;CH3C6H5 外观与性状 无色透明液体,有类似苯的芳香气味
分子量 92.14 蒸汽压 4.89kPa/30℃ 闪点:4℃
熔 点 -94.4℃ 沸点:110.6℃ 溶解性 不溶于水,可混溶于苯、醇、醚等多数有机溶剂
密 度 相对密度(水=1)0.87;相对密度(空气=1)3.14 稳定性 稳定
危险标记 7(易燃液体) 主要用途 用于掺合汽油组成及作为生产甲苯衍生物、炸药、染料中间体、药物的主要原料

健康危害

侵入途径:吸入、食入、经皮吸收。
健康危害:对皮肤、粘膜有刺激性,对中枢神经系统有麻醉作用。
急性中毒:短时间内吸入较高浓度本品可出现眼及上呼吸道明显的刺激症状、眼结膜及咽部充血、头晕、头痛、恶心、呕吐、胸闷、四肢无力、步态蹒跚、意识模糊。重症者可有躁动、抽搐、昏迷。
慢性中毒:长期接触可发生神经衰弱综合征,肝肿大,女工月经异常等。皮肤干燥、皲裂、皮炎。


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