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How does the acid-base indicators change the colour of a substance?
Wiki User
∙ 12y ago
Most indicators we meet in early science are acid base indicators and conform to this definition. However there are other types of indicator which can show up other types of chemical. For instance we use diphenylamine to show up the end point of the reaction between Fe2+ and potassium dichromate, and lead acetate paper to test for hydrogen sulfide.
Wiki User
∙ 8y ago
Wiki User
∙ 11y agoUniversal Indicator is a chemical (water, propan-1-ol, phenolphthalein sodium salt, sodium hydroxide, methyl red, bromothymol blue monosodium salt and thymol blue monosodium salt) that "indicates" wether a soloution is Acidic or Alkali (Basic) by changing colour.
Red, Orange, Yellow = Acid
Green = Neutral (pH 7)
Blue, Violet, Purple = Alkali
Wiki User
∙ 12y agoThey don't. The indicator substance itself changes colour due to the change in concentration of H+ ions involved in pH. (pH= -log[H+] ).
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Can indicators change colour twice?
Yes.
What is an 'indicator reaction'?
---- indicators are substances which change their colour when treated with acidic or basic solutions this reaction of changing their colour is known as indicator reaction ---- ----
What are the six characteristics of a chemical change?
1. evolution of a gas 2. change in colour of the substance 3. change in temperature of the substance 4. formation of precipitate
What is a sign of a reaction oh a chemical change?
a colour change, a gas produced or a precipitate (new substance/solid) formed.
Which indicator could be used to identify a neutral solution?
there is no such indicator.the only way is to add the acidic and basic indicators ,if it does not change the colour of the solution then it is neutral.
What do indicators tell us?
Indicators are used to tell a person whether or not a chemical is present or what pH a substance may be. Usually an indicator is a strip that is dipped into the substance and will change color based on the presence of a substance or pH.
Can indicators change colour twice?
Yes.
Which of the following is a definite indicator that a chemical change has occured?
Definite indicators of a chemical reaction include exothermic reactions (heat), colour change, bubbles and there might be a few morea new substance forms (study island)
Why indicator change color?
Indicators are mostly organic aromatic compounds in acidic to basic medium or vice versa the resonating structures of indicators become change which are responsible to change the colour.
If you are trying to decide whether a chemical reaction does or does not take place when two substances are mixed what kind of evidence will you look for?
change of state change of colour fizzing/gas bubbles
What is an 'indicator reaction'?
---- indicators are substances which change their colour when treated with acidic or basic solutions this reaction of changing their colour is known as indicator reaction ---- ----
What substance in cigarette causes the blood to change colour?
nickateen
Why do indicators change colors?
indicators change colour because of your pee.
What are the six characteristics of a chemical change?
1. evolution of a gas 2. change in colour of the substance 3. change in temperature of the substance 4. formation of precipitate
What is another substance will chANGE COLOUR OTHERT THAN RED CABBAGE?
G
How do plants like morning glory or hydrangea act as indicators of the soils pH level?
they change colour on reaction to soil pH
Is an organic compound that changes color in an acid or base?
This might not be your answer, but universal indicators change colour when they come in contact with a substance. It will then change to the colour of its corresponding pH. So, in terms of bases, it turns from a turquoise (from green which is pH7) to a dark purple the more alkaline it is(<7-14) and in terms of acids, it goes from a green-yellow to a dark red (>7-0).
