Anyway, how did you memorize the color change law of litmus and phenolphthalein in the first place?

The color change of litmus and phenolphthalein as indicators of acid-base neutralization is not the same.

1. If litmus and phenolphthalein are dropped into mol l of acetic acid and acidic solution, respectively: the solution dropped into litmus shows red, and the solution dropped with phenolphthalein is colorless. The colors are not the same.

2. If litmus and phenolphthalein are dropped into mol l of sodium carbonate acid and alkaline solution respectively: the solution dropped into litmus shows blue, and the solution dropped with phenolphthalein is red, and the color is different.

There is no need to use any mantra in this way. Very simply, litmus turns red when it is acid, and blue when it is alkaline; Phenolphthalein turns red when exposed to alkali. That's it, just remember.

Red alkali blue sartrate.

Phenolic acid is alkali-free red.

In turn, phenolphthalein turns red when it encounters alkali (it is not remembered when it does not change when it is acidic).

Purple litmus turns red when it is acid, and blue when it is alkaline.

Phenolphthalein is best remembered to only encounter one discoloration.

To be honest, I didn't memorize any mantras at all. It's also easy to confuse.

Straightforward, experiment with it, and you'll remember it quickly.

Purple litmus, red in acid, blue in alkali.

Colorless phenolphthalein, unchanged in acid, reddish in alkali.

It's very simple, just apply for an experiment.

The litmus is really beautiful when it changes color, and it remains unchanged in the acid red and alkali blue.

The discoloration of phenolphthalein is also good-looking, and the alkali makes phenolphthalein red and bright.

It's a bit vulgar, easy to remember.

The formula for phenolphthalein litmus discoloration is: phenolphthalein turns red when exposed to alkali, and does not change color when exposed to acid. Acid red alkali blue is litmus, phenolphthalein is red when exposed to alkali, and does not change color when exposed to acid.

The indicator changes color when it encounters acid and alkali solutions: "Litmus turns red when it encounters acid, and phenolphthalein disappears when it encounters acid; Litmus turns blue when it encounters alkali, and phenolphthalein turns red when it encounters alkali. Description: "No trace" means that the colorless phenolphthalein test solution does not change color (still colorless) when exposed to acid.

Litmus meets alkali", phenolphthalein meets alkali", the alkali here refers to the alkali solution, if it is an insoluble alkali, it cannot change the color of the indicator.

The formula for phenolphthalein and litmus when it meets acidity and alkali is sour carthol no, alkali stone blue phenol red, which means that litmus turns red when it encounters acid, phenolphthalein becomes colorless when it encounters acid, litmus turns blue when it encounters alkali, and phenolphthalein becomes red when it encounters alkali.

Acid-base indicators commonly used in high school chemistry are methyl orange, litmus and phenolphthalein.

The discoloration of methyl oranges ranges from 3.1 to 4.4, less than 3.1 is red, between 3.1 and 4.4 is orange, and more than 4.4 is yellow.

The litmus solution has a discoloration range of 5 to 8Less than 5 is red, between 5 and 8 is purple, and greater than 8 is blue.

The discoloration of phenolphthalein test solution ranges from 8.2 to 10Less than 8 o'clock 2 is colorless, between 8 o'clock 2 and 10 is light red, and more than 10 is red.

Turning them into mantras helps with memory. Such as:

Methyl orange: Methyl orange three or four dots (orange).

Phenolphthalein: Mrs. 80 red face in (red).

Litmus: Ten Maidens Dance (58) Purple flowers bloom (5-8 are purple).

Acid-base indicators are generally organic weak acids or weak bases, and their conjugated acid-base pairs have different structures and different colors. When the pH of the solution changes, the indicator gets protons, which change from basic to conjugated acid, or loses protons, which change from acid to conjugated base, and the color changes due to the transformation of its structure.

Methyl orange: Methyl orange three or four dots (orange).

Phenolphthalein: Mrs. 80 red face in (red).

Litmus: Ten Female Dance (58) Purple Blossoms (5-8 is purple) As for the formula, it is really impractical, it depends on the personal situation.

To be honest, I didn't memorize any mantras at all. It's also easy to confuse.

Straightforward, experiment with it, and you'll remember it quickly.

Purple litmus, red in acid, blue in alkali.

Colorless phenolphthalein, unchanged in acid, reddish in alkali.

It's very simple, just apply for an experiment.

1. Litmus indicator solution: discoloration range red and blue).

2. Phenolphthalein indicator solution: colorless red in the discoloration range).

3. Litmus indicator solution: take 10g of litmus powder, add 40ml of ethanol, reflux and boil for 1 hour, stand still, pour off the supernatant, and then treat it twice with the same method, each time with 30ml of ethanol, wash the residue with 10ml of water, pour off the lotion solution, add 50ml of water to boil, cool, filter, and obtain. Discoloration range (red, blue).

4. Phenolphthalein indicator solution: take 1g of phenolphthalein and add 100ml of ethanol to dissolve. Discoloration range: colorless, red).

1. The purple litmus solution turns red when the acidic solution is encountered.

2. The purple litmus solution turns blue when the alkaline solution is encountered.

3. Colorless phenolphthalein solution, no discolor in acidic solution.

4. Colorless phenolphthalein solution, which turns red when alkaline solution.

The litmus test solution turns red when it encounters acid, turns blue when exposed to alkali, and the phenolphthalein test solution is colorless when exposed to acid and turns red when exposed to alkali.

What color does litmus change when it is acid, come in and take a look.

Litmus is an organic weak acid denoted by hl.

It undergoes partial ionization in water.

hl = h+ +l-

Red, blue.

Neutral environment HL and L- coexist in solution.

So the red and blue mix is purple litmus.

In an acidic environment, there are too many hydrogen ions in the solution, and the ionization moves to the left, and the solution appears red.

In an alkaline environment, the hydroxide ions in the solution neutralize the hydrogen ions, and the ionization moves to the right, and the solution appears blue.

Phenolphthalein is an organic weak acid, acidic environment, when the concentration is high, the formation of colorless molecules.

In the alkaline environment, the phenolphthalein structure is changed, and it ionizes into a red ion into a quinone structure, but the discoloration range of phenolphthalein is pH.

The quinone structure of phenolphthalein, when the pH is greater than 10, it will slowly be converted into a colorless carboxylate formula Diagram of the structure of phenolphthalein