| 查看: 606 | 回复: 2 | |||
| 【悬赏金币】回答本帖问题，作者zhangajin将赠送您 20 个金币 | |||
zhangajin金虫 (小有名气)
|
[求助]
求助翻译以下两段英文 已有2人参与
|
||
|
In a 4-l. beaker, 290 cc. of water is heated to boiling, and 260 g. (1.1 moles) of crystallized sodium sulfide (Na2S·9H2O) and 34 g. of powdered sulfur are dissolved by heating and stirring. A solution of 40 g. of sodium hydroxide in 100 cc. of water is then added and the mixture cooled, first in cold water, and finally by a freezing mixture of ice and salt. In a 2-l. beaker, set in a freezing mixture and provided with a stirrer and a thermometer for reading temperatures to 0°, are placed 500 cc. of water, 137 g. (1 mole) of anthranilic acid, and 200 cc. of concentrated hydrochloric acid; the stirrer is started and the mixture cooled to about 6°. Meanwhile 69 g. (1 mole) of sodium nitrite is dissolved in 280 cc. of hot water and the solution cooled in ice; portions are then placed in a separatory funnel of convenient size, supported in such a way that the lower end of the stem extends beneath the surface of the anthranilic acid solution. When the temperature has fallen to 5°, the nitrite solution is run in; about 500 g. of cracked ice is added at such a rate as to keep the temperature below 5°. This takes about ten minutes (Note 1). A drop of the solution should give an immediate blue color with starch-iodide paper. The stirrer and thermometer are now transferred to the alkaline sulfide solution, the temperature of which must be below 5°. The diazo solution is added over a period of twenty to thirty minutes along with 950 g. of ice to prevent the temperature from rising above 5°. When addition is complete, the water bath is removed and the mixture allowed to warm up to room temperature; after two hours the evolution of nitrogen ceases (Note 2). About 180 cc. of concentrated hydrochloric acid is added until the solution is acid to Congo red paper, and the precipitate of dithiosalicylic acid is filtered and washed with water. |
回复此楼» 猜你喜欢
本9 一志愿西工大085601 324求调剂
已经有4人回复
-
一志愿东北大学控制工程085406数二英二385，求调剂
已经有6人回复
-
272分材料子求调剂
已经有22人回复
-
0856专硕求调剂 希望是a区院校
已经有23人回复
-
346，工科0854求调剂，专硕
已经有5人回复
-
337求调剂
已经有3人回复
-
266求调剂
已经有29人回复
-
309求调剂
已经有13人回复
-
一志愿0703化学招61最终排名62化学求调剂
已经有28人回复
-
286求调剂
已经有7人回复
感谢参与，应助指数 +1
|
本帖内容被屏蔽 |
2楼2015-08-24 11:36:12
krispanlove
金虫 (小有名气)
- 应助: 26 (小学生)
- 金币: 719.4
- 红花: 21
- 帖子: 254
- 在线: 29.1小时
- 虫号: 3898944
- 注册: 2015-05-30
- 性别: MM
- 专业: 环境工程
3楼2015-08-24 17:33:12
