影子
第2楼2008/01/23
好吧.
Dissolve 40.0 g of sample in carbon-dioxide free water. Allow to cool. Transfer this solution to a 1000ml volumetric flask and dilute to mark with the same water. Lable the solution as solution A. Pipet the solution A 20ml to a 500ml volumetric flask and dilute to the mark with the same water. Further pipet 20ml to a 100ml beaker, add 1 drop of methyl red indicator, then add acetic acid until the solution remains light-red. After heating the solution to 40ºC, 8-9ml of 0.1mol/L sodium tetraphenylborate -ethanol solution is dropwise added with agitating in 5 minutes. After addition, allow to stand for 10 minutes. Filter the mixture with a G4 glass crucible previously dried in a 115-125ºC oven until a constant weight was obtained. Wash the filter cake 8-10 times with each 5-ml potassium tetraphenylboron saturated solution. Then wash the filter cake once with 2ml of anhydrous ethanol. Dry the crucible in a 115-125ºC oven until a constant weight obtained.
闲鹤野云
第3楼2008/01/24
用称量瓶迅速称取样品40g,溶解于新煮沸并冷却的水中,冷却,移入1000ml容量瓶中,用新煮沸并冷却的水稀释至刻度,摇匀,作为溶液甲。
Weigh 40g sample (with weighing vial) promptly and dissolve it into freshly boiled and cooled water. Let the solution cool down and transfer it to a 1000ml volumetric flask. Added to volume with freshly boiled and cooled water, mixed, then used as solution A.
何当奇
第4楼2008/01/24
Dissolve (+ rapidly) 40.0 g of sample in carbon-dioxide free (or cool fresh-boiled) water. Allow to cool (+ down). Transfer this solution to a 1000ml volumetric flask and dilute to mark with the same water. Lable (应为Label) the solution (可以去掉) as solution A. Pipet the solution A 20ml (Pipet 20 ml of solution A) to a 500ml volumetric flask and dilute to the mark with the same water. (少了一句) Further pipet 20ml (+ the above solution) to a 100ml beaker, add 1 drop of methyl red indicator, then add acetic acid until the solution remains light-red. After heating the solution to 40ºC, 8-9ml of 0.1mol/L sodium tetraphenylborate -ethanol solution is dropwise added with agitating in ( within )(c.)5 minutes. (前面主动,这里被动,似乎不是很和谐。尽量保持一致吧,很多时候我也犯同样的错误) After addition, (“then” is enough) allow to stand for 10 minutes. Filter the mixture with a G4 glass crucible previously dried in a 115-125ºC oven (这个句中没有) until a constant weight was obtained (“until constant weight” is enough). Wash the filter cake (好像都用sediment) 8-10 times with each 5-ml potassium tetraphenylboron saturated solution. (Wash the sediment using 40-50 ml of otassium tetraphenylboron saturated solution at 8- 10 times). Then wash the filter cake once ( one time) with 2ml of anhydrous ethanol. Dry the crucible in a 115-125ºC oven until a constant weight obtained. (or “dry to constant weight at 120±5℃)
poorlittle
第7楼2008/01/24
As metrology is one of my routine jobs, I am very sensitive to the figures. I wonder why “取样品40g” was translated as 40.0g.
“boiled and cooled water” seems to be more common than “cool fresh-boiled” as I found about 17300 results in google when searching with the key words “boiled and cooled”, water. (1150 results with the key words "boiled then cooled", water)