close
標題:
最佳回答40分：通用指示劑有甚麼化學成分﹖
最佳回答40分：通用指示劑有甚麼化學成分﹖
最佳解答:
http://zh.wikipedia.org/wiki/%E6%8C%87%E7%A4%BA%E5%89%82 酸鹼指示劑 有酚酞、甲基红、甲基橙等 http://zh.wikipedia.org/wiki/%E9%85%B8%E7%A2%B1%E6%8C%87%E7%A4%BA%E5%89%82 酚酞:http://zh.wikipedia.org/wiki/%E9%85%9A%E9%85%9E 甲基橙:http://zh.wikipedia.org/wiki/%E7%94%B2%E5%9F%BA%E6%A9%99 甲基红:http://zh.wikipedia.org/wiki/%E7%94%B2%E5%9F%BA%E7%BA%A2 氧化还原指示剂 氧化还原指示剂用在氧化还原滴定中，在试液的电位改变时可以迅速的改变颜色。 有些氧化还原指示剂因发生氧化还原反应而变色，如“蓝瓶实验”中的亚甲基蓝。还有一些指示剂变色时发生配合反应，这些指示剂仅用于有特定反应物或生成物的反应，如淀粉在碘量法实验中的使用。 如果指示剂的氧化还原变色反应涉及质子，那么使用时还应考虑溶液酸碱性对变色范围的影响。 值得注意的是，有些氧化还原滴定反应的反应物在反应前后有明显颜色变化，如高锰酸钾等，这类物质滴定时本身可以起到指示剂的作用，但它们不是指示剂。 酸鹼指示劑的較多,看看上面的網址 2007-05-19 22:13:58 補充： 石蕊和酚酞最常用石蕊:http://zh.wikipedia.org/wiki/石蕊酚酞:http://zh.wikipedia.org/wiki/酚酞
其他解答:
This article is about the chemical pH indicator. For the musical artists, see Universal Indicator (music). Universal Indicator is a pH indicator that has different colors to indicate the range of the pH of the solution it is in. This is opposed to indicators like phenolphthalein which have only two different colors and are able to indicate only whether the pH is above or below a certain point by using the various pH values of the indicators. It usually has the following composition: Methanol(455) Propan-1-ol Water Phenolphthalein, sodium salt Methyl red, sodium salt Thymol blue, sodium salt Bromthymol blue, sodium salt Universal indicator is a flammable liquid. It may cause respiratory tract irritation. Prolonged or repeated contact may cause dry, cracked skin, irritation or kidney damage. It may also form explosive peroxides. [edit] Colors and meanings Very acidic - Red Acidic - Orange/Yellow Neutral - Green Basic/base/alkali - Blue Very basic/base/alkali - Purple The colors follow those of the visible spectrum of light. The pH number is compared with the color. Anything below 7 is acidic (the lower, the stronger it is acidic), 7 is neutral (neither acidic or alkali) & anything above 7 is alkali (the higher it is, the more alkaline it is). This is easily demonstrated when you put blue litmus paper inside the beaker, it will change its natural alkalinity to a duller/ darker color if it is of a high pH, or a radiant/ brighter color if it is of a low pH. [edit] More details Physical state: Liquid Appearance: light green in water solvent; dark green alone Odour: alcohol-like pH value: Approximately 7 Vapour pressure: 25 mmHg (3.3 kPa) Vapour Density: 1.3 kg/m3 Boiling point: 80 °C Solubility: Soluble in water. Specific gravity/Density: 0.93 g/cm3 Molecular formula: Mixture
最佳回答40分：通用指示劑有甚麼化學成分﹖
此文章來自奇摩知識+如有不便請留言告知
發問:最佳回答40分：通用指示劑有甚麼化學成分﹖
最佳解答:
http://zh.wikipedia.org/wiki/%E6%8C%87%E7%A4%BA%E5%89%82 酸鹼指示劑 有酚酞、甲基红、甲基橙等 http://zh.wikipedia.org/wiki/%E9%85%B8%E7%A2%B1%E6%8C%87%E7%A4%BA%E5%89%82 酚酞:http://zh.wikipedia.org/wiki/%E9%85%9A%E9%85%9E 甲基橙:http://zh.wikipedia.org/wiki/%E7%94%B2%E5%9F%BA%E6%A9%99 甲基红:http://zh.wikipedia.org/wiki/%E7%94%B2%E5%9F%BA%E7%BA%A2 氧化还原指示剂 氧化还原指示剂用在氧化还原滴定中，在试液的电位改变时可以迅速的改变颜色。 有些氧化还原指示剂因发生氧化还原反应而变色，如“蓝瓶实验”中的亚甲基蓝。还有一些指示剂变色时发生配合反应，这些指示剂仅用于有特定反应物或生成物的反应，如淀粉在碘量法实验中的使用。 如果指示剂的氧化还原变色反应涉及质子，那么使用时还应考虑溶液酸碱性对变色范围的影响。 值得注意的是，有些氧化还原滴定反应的反应物在反应前后有明显颜色变化，如高锰酸钾等，这类物质滴定时本身可以起到指示剂的作用，但它们不是指示剂。 酸鹼指示劑的較多,看看上面的網址 2007-05-19 22:13:58 補充： 石蕊和酚酞最常用石蕊:http://zh.wikipedia.org/wiki/石蕊酚酞:http://zh.wikipedia.org/wiki/酚酞
其他解答:
This article is about the chemical pH indicator. For the musical artists, see Universal Indicator (music). Universal Indicator is a pH indicator that has different colors to indicate the range of the pH of the solution it is in. This is opposed to indicators like phenolphthalein which have only two different colors and are able to indicate only whether the pH is above or below a certain point by using the various pH values of the indicators. It usually has the following composition: Methanol(455) Propan-1-ol Water Phenolphthalein, sodium salt Methyl red, sodium salt Thymol blue, sodium salt Bromthymol blue, sodium salt Universal indicator is a flammable liquid. It may cause respiratory tract irritation. Prolonged or repeated contact may cause dry, cracked skin, irritation or kidney damage. It may also form explosive peroxides. [edit] Colors and meanings Very acidic - Red Acidic - Orange/Yellow Neutral - Green Basic/base/alkali - Blue Very basic/base/alkali - Purple The colors follow those of the visible spectrum of light. The pH number is compared with the color. Anything below 7 is acidic (the lower, the stronger it is acidic), 7 is neutral (neither acidic or alkali) & anything above 7 is alkali (the higher it is, the more alkaline it is). This is easily demonstrated when you put blue litmus paper inside the beaker, it will change its natural alkalinity to a duller/ darker color if it is of a high pH, or a radiant/ brighter color if it is of a low pH. [edit] More details Physical state: Liquid Appearance: light green in water solvent; dark green alone Odour: alcohol-like pH value: Approximately 7 Vapour pressure: 25 mmHg (3.3 kPa) Vapour Density: 1.3 kg/m3 Boiling point: 80 °C Solubility: Soluble in water. Specific gravity/Density: 0.93 g/cm3 Molecular formula: Mixture
文章標籤
全站熱搜
留言列表
