4.1 氢氧化钠标准溶液Standard sodium hydroxide solution
称取100g氢氧化钠,溶于100ml水中, 摇匀, 注入聚乙烯容器中, 密闭放置至溶液清亮, 用塑料管虹吸下述规定体积的上层清液, 注入1000ml 无二氧化碳的水中, 摇匀,.
To take 100g of sodium hydroxide, dissolve it in 100ml of water, shake up, inject it into a polyethylene vessel and seal the vessel to leave it until the solution become clear. To suck the volume of clear liquid on the surface of the solution specified below with a plastic tube, inject in into water without carbon dioxide and shake up.
C(NaOH)=0.1mol/L 氢氧化钠饱和溶液 ml
Saturated solution of sodium hydroxide, ml
1 52
0.5 26
0.1 5
4.1.2标定 Calibration
4.1.2.1 测定方法 Measuring method
称取下述规定量的于105-110OC洪至恒重的基重邻苯二甲酸氢钠, 称准至0.0001g, 溶于下述规定体积的无二氧化碳的水中, 加两滴酚酞指示液,(10g/l),用配制好的氢氧化钠溶液滴定至溶液呈粉红色, 同时作空白实验.
To take specified quantity of reference potassium hydrogen phthalate that is dried to constant weight at 105-110Oc, the accuracy shall be 0.0001g, dissolve it in the specified volume of water without carbon dioxide, and add 2 drops of phenolphthalein indicating liquid(10g/l), and then with the confected sodium hydroxide solution to titrate until the solution become pink in color. At the same time , blank test shall be performed.
C(NaOH) mol/L reference potassium hydrogen phthalate, g carbon dioxide-free water ml
1 6 80
0. 5 3 80
0. 1 0. 6 50
4.1.1.2计算 Calculation
氢氧化钠标准溶液的浓度按式(1)计算:
The concentration of standard sodium hydroxide solution shall be calculated according to formula (1):
C ( NaOH ) =m/(v1-v2)*0.2042--------------------------------------------------------------(1)
式中: C (NaOH) 氢氧化钠标准溶液之物质的量浓度, mol/L
M—邻苯二甲酸氢钾之质量, g;
M – mass of potassium hydrogen phthalate, g
V1—氢氧化钠溶液之用量, ml;
V1—dosage of sodium hydroxide solution, ml
V2—空白试验氢氧化钠溶液之用量,ml;
V2—dosage of sodium hydroxide solution required for blank test, ml
0.2042---与1.00 g氢氧化钠标准溶液[C(NaOH)=1.0000mol/L]相当的以克表示的邻苯二甲酸氢钾的质量;
0.2042---mass of potassium hydrogen phthalate in gram equivalent to 1.00ml of standard sodium hydroxide solution [C(NaOH)=1.0000mol/L]
4.1.3 比较 Comparison
4.1.3.1 测定方法 measuring method
量取30.00-35.00ml下述规定浓度的盐酸标准溶液, 加50ml无二氧化碳的水及2滴酚酞指示剂, (10g/L)用配制好的氢氧化钠溶液滴定, 近终点时加热至80 oc, 继续滴定至溶液呈粉红色.
To take 30.00—35.00ml of standard hydrochloric acid solution, the concentration of which is specified below, add 50ml of carbon dioxide-free water and 2 drops of phenolphthalein indicating liquid(10g/L), and then with the confected sodium hydroxide solution to titrate. To heat it to 80 Oc when titration is close to the end and continue to titrate until the solution become pink in color.
C (NaOH) 0.1ml/L C (HCl) mol/l
1 1
0. 5 0. 5
0. 1 0. 1
4.1.3.2 计算Calculation
氢氧化钠标标准溶液的浓度按式2计算
The concentration of standard sodium hydroxide solution shall be calculated according to formula (2)
C(NaOH)=V1*C1/V--------------------------------------------------------------------(2)
式中 C(NaOH)氢氧化钠标准溶液之物质的量浓度; mol/L
where C(NaOH)—measuring concentration of substance in standard sodium hydroxide, mol/L
V1—盐酸标准溶液之用量 ml
V1—dosage of standard hydrochloric acid solution, ml
C1—盐酸标准溶液之物质的量浓度 mol/L
C1—measuring concentration of substance in standard hydrochloric acid mol/L
V – 氢氧化钠溶液之用量 ml V--- dosage of standard sodium hydroxide solution , ml
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