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Anonymous users2024-02-07Vinegar used at home contains acetic acid, and human gastric juice contains a small amount of hydrochloric acid to help digestion. Alkaline noodles used for home dough are alkaline substances. Some of the chemical fertilizers in agricultural production are acidic and some are alkaline. Acidic and alkaline substances have a wide range of applications in the daily life of industrial and agricultural production.
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Anonymous users2024-02-061. Vinegar
Vinegar is a traditional condiment in Chinese cuisine. According to the existing written records, the ancient Chinese working people used wine as a starter to ferment and brew vinegar, and oriental vinegar originated in China, and the history of vinegar brewing according to literature is at least more than 3,000 years.
2. Dish soapDish soap, daily cleaning products. Clean and mild, soft foam, rapid decontamination, sterilization, effective and thorough cleaning, no residue, exude a light and elegant fruit fragrance, white and bright after washing. Use it frequently to ensure home hygiene and avoid the spread of germs.
3. Laundry detergentLaundry detergent is an alkaline synthetic detergent that is a chemical agent used to wash clothes.
The main ingredients of laundry detergent are anionic surfactants, sodium alkylbenzene sulfonate, a small amount of nonionic surfactants, plus some additives, phosphate, silicate, yuanming powder, fluorescent agent, enzyme, etc., which are made by mixing, spraying and other processes, and now most of them use 4A fluorite instead of phosphate. Laundry detergent refers to a synthetic detergent in powder form (granular).
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Anonymous users2024-02-05acid
What is the first thing that comes to your mind when you see this word? - Sour taste! Therefore, in life, people often think that substances with a sour taste are acids.
For example, vinegar, green apple, lemon, bayberry, kimchi, yogurt, ......However, it is dangerous to determine whether a substance is an acid or not by tasting the taste, because not all acids can be eaten, and there are many acids that are strongly corrosive and cannot be eaten.
AlkalisWe often hear about acids, but alkalis, which usually appear with acids, are less well known. Relatively speaking, you may think of alkali as a relatively unfamiliar class. Is that really the case?
Pastries, chili peppers, soda, soap, shampoo, detergents, stomach relief ...... eaten when you have stomach bloating and stomach painYou've eaten or used all of these things, and they all contain a certain concentration of alkaline substances.
Compared to acid, alkali is less "gentle" and is usually bitter, astringent, and spicy, but if it is processed properly with other foods, it can also be delicious.
Acids and alkalis can play their role according to their properties, for example, dilute hydrochloric acid can remove rust, concentrated sulfuric acid can be used as a catalyst for many productions, nitric acid can be used in a large number of factories to produce nitrogen dioxide, sodium hydroxide is also a catalyst for many organic reactions, and hydrated lime can neutralize the acidity of the soil. Uses: used in textiles, papermaking, soap, plastics, dyes, refined petroleum, etc.
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Anonymous users2024-02-04Acids commonly used in life: vinegar (containing acetic acid, also called acetic acid), yogurt, formic acid secreted by ants, stomach acid, apples, grapes, lemons, various fruits, various carbonated drinks, such as cola, sprite, etc.
Alkali commonly used in life: face alkali (sodium carbonate), lime (calcium carbonate), laundry detergent, soap, toothpaste, milk, human saliva, etc.
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Anonymous users2024-02-03The acidity or alkalinity of a substance refers to the acidic or alkaline properties exhibited by the substance in an aqueous solution.
Expand your knowledge:
1.Acidic substances
Acidic substances refer to chemical substances that exhibit acidic properties in aqueous solutions, such as acidic odors, corrosion of metals, and so on. Common acids are hydrochloric acid, sulfuric acid, acetic acid, etc.
2.Alkaline substance Wangling
Alkaline substances refer to chemical substances that exhibit alkaline characteristics in aqueous solutions, and have the chemical properties of alkaline solutions, such as showing bitter taste, strong alkaline, and can neutralize with acids. Common alkaline substances are sodium hydroxide, ammonia, caustic soda, etc.
3.Neutral substances
Neutral substances refer to chemical substances that exhibit neutral properties in aqueous solutions, which may be inorganic substances or organic substances, such as ethanol, water, etc. The neutral substance is neither acidic nor alkaline and has a pH of about 7.
value
pH is an indicator of how acidic or basic a substance is in solution, with values ranging from 0 to 14. At a pH of 7, the solution is considered neutral; Less than 7 is considered acidic; A greater than 7 is considered alkaline. Therefore, pH value is one of the important indicators to evaluate the acidity and alkalinity of a substance.
5.Acid-base indicator
An acid-base indicator is a chemical substance that is capable of color change depending on the pH of a solution and is used to determine the acidity or alkalinity of a solution. Common acid-base indicators include phenolphthalein, fresh rubin, bromophenol blue, etc., and different indicators correspond to different pH ranges.
To sum up, the acidity and alkalinity of a substance refers to the acidic or alkaline characteristics of the substance in the aqueous solution, the acidic substance is represented by hydrochloric acid and sulfuric acid, the alkaline substance is represented by sodium hydroxide and caustic soda, and the pH value and acid-base indicator are important indicators and tools to evaluate the acidity and alkalinity of the substance. By understanding and mastering the acidity and alkalinity of substances, we can help us better understand some phenomena in the field of chemistry.
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Anonymous users2024-02-02When a compound is soluble in water.
When free ions are generated.
Its positive H+ concentration》 1 1000000
This is an acidic substanceFor example: hcl --in water---h+ +cl-
Therefore, hydrochloric acid should be dissolved in water.
its H+ ion concentration.
It must be more than 1 1000000Similarly, if a CPD is dissolved in water, its negative ion OH- is more than 1 1000000, for example, NAOH--- water--- Na+ + OH- some nuclear hail nuclei produce OH- more than 1 1000000, which is an alkaline substance
An important factor in determining pH is the concentration of hydrogen ion activity (sometimes written as [H3O+], hydronium ion modified activity) in the [H+] solution contained in the originator. The higher the [H+] concentration value, the more acidic, and the lower the [H+] concentration value, the more alkaline it is.
You can use pH test strips for a wide range of reagents (pH test strips), also known as general purpose indicators or general use reagents. Generally, it is used to indicate the acidity and alkalinity of the solution, and can indicate various pH values in the acidic and alkaline range, and the pH range of its discoloration is as follows: The indicated pH value 4 5 6 7 8 910 The color of the wide range of reagents Red, orange, yellow, green, blue, indigo, violet pH value<4, the color is red pH value》10, the color is purple The wide range reagent is a kind of pH indicator, and its applicable range is pH3 12, which can be used to show the pH of different solutions.
Although there are many different and wide range of reagents on the market, most of them are variations of Yamada's proprietary formulations. Details of this patent can be found in Chemical Abstracts. Yamada's experiments on a wide range of reagents were also published in the Journal of Chemical Education.
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Anonymous users2024-02-01The role of acid and base in life is as follows:
1. It can help the human body digest and absorb food, and the hydrogen ion pump of the stomach digestion is directly motivated;
2. Alkali metal ions complete the circulation of neurotransmitters and body fluids in the body;
3. Sodium and potassium ions are required for the transport of substances inside and outside the cell, and divalent iron ions are required for the absorption of oxygen.
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Anonymous users2024-01-31Solution ideas: (1) The acidity of gastric juice is due to the fact that it contains hydrochloric acid, and aluminum hydroxide will have a neutralization reaction with hydrochloric acid
2) Acid reacts with carbonate to produce carbon dioxide gas, and alkaline substances can neutralize with acid;
3) Quicklime and water will produce calcium hydroxide
1) The hydrochloric acid in the gastric juice reacts with the aluminum hydroxide in the drug to form aluminum chloride and water The chemical equation of the reaction is Al(OH)3+3HCl, ALCL3+3H2O
2) Lactic acid reacts with soda ash or baking soda to generate carbon dioxide gas, making steamed bread soft and empty If too much alkaline substance is added, steamed bread will become astringent, and even affect human health Therefore, to neutralize with acid, acetic acid (CH3COOH) can be used
3) What occurs in lime milk is the reaction of calcium oxide and water to calcium hydroxide, and the chemical equation of this reaction is: CaO+H2O Ca(OH)2
So the answer is: (1) aluminum hydroxide or Al(OH)3; 3hcl+al（oh）3═alcl3+3h2o
2）co2；vinegar or CH3COOH;
3）cao+h2o═ca（oh）2
Comments: Test points for this question: Neutralization reaction and its application; the properties and uses of raw lime; chemical properties of salt; Write chemical equations, verbal expressions, ionization equations
Test Center Comments: This question is an examination question for the reaction between substances, and the key to solving the problem is to use the existing knowledge to analyze the problem, which is a basic knowledge examination question
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Anonymous users2024-01-301. Basic substances refer to substances that have the ability to donate electrons or the ability to accept protons.
2. Alkaline substances include detergent, laundry detergent, soap, battery, cement, lime water, baking soda, edible alkali, etc. An alkaline substance is a substance that has the ability to donate electrons or the ability to accept protons. According to the characteristics of the substance, it can be divided into organic alkali and inorganic alkali, according to the amount of proton that the substance can accept, it can be divided into monobasic alkali, dibasic alkali, ternary alkali, polyalkali, etc., and according to the alkalinity of the substance, it can be divided into strong alkali and weak alkali.
Alkaline foods include vegetables, tea, fruits (except high-sugar fruits), soy products, milk, etc.
There are acidic foods and alkaline foods in the daily diet. From a nutritional point of view, it is also called acid-forming food and alkaline food. They directly affect the pH of human body fluids. >>>More
Acidic foods are almost all acidic, such as fish, meat, rice, wine, sugar, etc., all of which are acidic foods, on the contrary, alkaline foods such as kelp, vegetables, white radish, tofu, etc., are mostly foods that are not easy to arouse appetite but are beneficial to the body. The layman's idea is that sour things are acidic foods, such as strawberries and lemons that will make your mouth water, but in fact, these things are typical alkaline foods, and the trouble lies in this place. >>>More
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The general formula of oxygenated acid can be written r-o-h like this, the easier it is to lose h, the more acidic it is. It depends on the force of the r-o side on h. The above three acids are the substitution of acetic acid in the two positions, only F, Cl and H are not the same, F and Cl have a certain electron withdrawing effect, but the F radius is smaller than Cl, and the electron withdrawing effect is larger than Cl, so the electrons are biased towards the R group, which reduces the electron cloud density on O, so that H is easier to remove, so the acid replaced by F is more acidic. >>>More