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transition interval
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What is meant by the transition interval of an indicator?
The pH range over which an indicator changes color.
How do you use a indicator?
pH indicators are usually weak acids or weak bases that change their color depending on their dissociation (protonation) state. Sometimes both forms are colored, sometimes only one. In most cases you may assume that to completely change color of bicolored indicator pH must change by 2 units. However, human eye is more sensitive to some colors than to others, thus some color changes can be perceived over wider pH range. pH indicators can be used to check pH of the solution, although they are rarely added directly. Only in acid-base titrations indicator should be added to the solution. To check pH it is much more convenient to use pH strips. It is worth of noting here that pH strips are nothing else but pieces of paper impregnated with indicator or a mixture of indicators.
How are universal indicators useful to scientist?
An Universal Indictator is more helpful because it shows the exact amount of acidity. Other indictators (example the red and blue litmus) just indicates whether or not the solution is acidic. The universal indicator gives you a specific color to which you can match a pH number therefore, telling you how acidic the soultion is.
How do you use phenophthalein to test for acids and bases?
Any titration is done to find the "equivalence point" - where the amount of titrant (strong base in your question) is equal to the amount of unknown (weak acid in your question). When the two are equal, the base has converted all the weak acid into it's conjugate base. An indicator should change color over the pH range that includes the equivalence point. In your question, when using a weak acid, what's left at the equivalence point is a strong conjugate base. The solution will have a slightly basic pH. Phenolphthalein has a colorless to pink transition over the range of pH 8-9.6, which is slightly basic. So it changes color across the equivalence point. So it makes a good indicator for the scenario you asked about. Thymol blue (color change slightly lower pH, weaker base, stronger acid) or Thymolphthalein (color change slightly higher pH, stronger base, weaker acid) may also be good choices.
What is paper indicator?
paper thet measures pH is the measure of the acidity or alkalinity of a solution. It is formally a measure of the activity of dissolved hydrogen ions (H+), but for very dilute solutions, the molarity (molar concentration) of H+ may be used as a substitute with little loss of accuracy.[1] In solution, hydrogen ions occur as a number of cations including hydronium ions (H3O+).[ Hydrion is a trademarked name for a popular line of compound pH indicators, marketed by Micro Essential Laboratory, Inc. exhibiting a series of color changes (typically producing a recognizably different color for each pH unit) over a range of pH values. Although solutions are available, the most common forms of Hydrion are a series of papers impregnated with various mixtures of indicator dyes. It is considered a "universal indicator".
What is meant by the transition interval of an indicator?
The pH range over which an indicator changes color.
What does a typical acid base indicator exhibit its colour change over range of?
Its colour changes over a range of Ph values.
Why does the typical base indicator exhibit its color change over a range of about 2 PH units?
The usual range of the color change on the indicator is between 1.5-2 pH units because of the sensitivity of the indicators. The universal indicator is used in most test.
What color is the universal indicator in an alkali?
Many soluble dyes change their color with changes in pH (a measure of the concentration of acid in a solution). Such dyes may be used to indicate when the acid (base) in a solution has been neutralized by addition of an equal amount of base (acid). Each indicator dye has a particular range of pH for which it is useful. pH test strips and papers often incorporate two or more dyes to extend the range of pH over which they can be used. The best indicator dyes are strongly colored (so that only small amounts are needed), undergo an easily seen change with pH (either from one color to another, or from clear to colored), are nontoxic, and are chemically stable.
Why you use two indicator?
Because the end-pointsof these titrationshave different pH values. A strong acid / strong base titration has an endpoint of pH 7, and an indicator that changes near 7 is useful. Phenolphthalein changes around pH 8.5 which is close enough for government work (so to speak).A strong acid - weak base titration will have an endpoint below 7, and so an indicator that changes over a range that is less than 7 should be used. Methyl orange changes around pH 4.
Why are mercury used in thermometer?
because it expands and contracts in a nice linear way as the temperature changes, which makes it easy to use as an indicator.
Which phenotypic change in genetic?
Changes that are genetic
What is work and how it changes over time?
It changed over time from black and white to color?
What is the specific name of universal indicator?
A Universal indicator is a pH indicator composed of a solution of several compounds that exhibits several smooth colour changes over a pH value range from 1-14 to indicate the acidity or basicity of solutions. A universal indicator is typically composed of water, propan-1-ol, phenolphthalein sodium salt, sodium hydroxide, methyl red, bromothymol blue monosodium salt, and thymol blue monosodium salt.
What is volatility in forex?
Volatility is the range in which the price of a financial instrument fluctuates and is one of the most significant indicators to highlight the attractiveness of a trading instrument. Volatility shows the extent of risk involved in using an instrument since the higher the indicator, the bigger the range in which the rate changes over a specified amount of time.
What is a lock in range and a capture range?
Lock range is the input frequency range of the PLL over which out frequency changes in step with input frequency, where as capture range is the frequency range over which oput starts to responds to input frequency change.
What do you use universal indicator solution for?
It is a chemical solution used for knowing the pH of a substance. Eg. You mix a drop of Universal indicator solution with approx 5 mL of the substance whose pH you want to know.You can compare the color with a standard pH chart and know the pH.
