Exploring the Properties of Acids and Bases in Everyday Substances

The program introduces the topic of acids and bases, highlighting how common substances like citrus fruits, medications, yogurt, and cleaning products contain acids or bases. It explains that acids have a sour taste, while bases have a bitter taste, and both can be dangerous if ingested.

Acids in foods like citrus juices (e.g., lemon, orange), medications (e.g., acetylsalicylic acid), yogurt (lactic acid), and vitamin C (ascorbic acid) give them a sour taste. However, tasting acids is risky as many are hazardous. The sour taste of foods indicates the presence of acids.

Bases, found in cleaning products and medications like antacids, have a bitter taste and a slippery feel similar to soap. However, tasting bases is dangerous as some are toxic and corrosive, such as caustic soda (sodium hydroxide). Bases can relieve stomach discomfort.

Identifying acids and bases by taste or smell is risky due to their potential hazards. Chemical substances that react differently to acids and bases can be used for identification. For example, some substances change color in the presence of acids or bases, providing a visual indicator of their nature.

pH indicators like red litmus paper turn red in the presence of an acidic solution and blue in a basic solution. Universal indicators change color to indicate acidity (red) or basicity (blue). These substances are known as acid-base indicators.

To prepare an acid-base indicator using red cabbage extract, gather materials like a chopping board, knife, mortar and pestle, amber-colored bottle, strainer, 100mL beaker, dropper, label, marker, spoons, color scale, alcohol, red cabbage leaves, oven cleaner, and hydrochloric acid. Extract the purple cabbage, filter the liquid, transfer it to the bottle, and label it. This homemade indicator can detect acids and bases.

By adding a few drops of the homemade indicator to a solution, observing a red color change indicates acidity. Comparing the color to a scale confirms the acidity level. Repeat the process with another solution to identify basicity. This method helps identify acids and bases without direct contact.

The pH scale ranges from 0 to 14, with values below 7 indicating acidity, above 7 indicating basicity, and 7 being neutral like water. Qualitatively, pH indicators show color changes, while quantitatively, the pH value determines the acidity or basicity of a substance.

Soap, a common product, can have basic or acidic properties. Some soaps are basic due to the presence of animal fats, vegetable oils, and sodium hydroxide. Sodium bicarbonate, also basic, is used in toothpaste to reduce mouth acidity and prevent cavities.

Vinegar is used to clean various stains in the kitchen, refrigerator, and bathrooms. It can remove dark stains inside a coffee maker by heating it with a little vinegar. Additionally, vinegar can eliminate limescale buildup around some pipes.

Vinegar can be obtained from wine by allowing it to come into contact with oxygen in the air. Acetobacter bacteria carry out aerobic fermentation, converting the alcohol in wine into acetic acid. Vinegar is versatile, serving as an important ingredient in meals to enhance flavor and as a food preservative.

Different taste sensations of sour and bitter are perceived in various regions of the tongue. The highest sensitivity to bitter taste is found at the back of the tongue, while sour taste is mainly detected on the posterior lateral regions. Salty taste is perceived on the anterior lateral regions and sweet taste on the tip of the tongue due to the distribution of taste buds.

Acids and bases have diverse industrial applications. For instance, sulfuric acid is used in car batteries, fertilizers, and paper production. Carbonic acid and phosphoric acid are found in carbonated beverages. Bases like sodium hydroxide are used in drain cleaners, paper manufacturing, paints, and textiles.

Acids and bases play a significant role in daily life. Alkaline batteries contain potassium hydroxide, while nitric acid is present in some metal cleaners. Various methods exist to identify the acidity or basicity of substances using different indicators. Acids and bases are commonly encountered in household products and industrial processes.

The next segment will explore what happens when an acid is mixed with a base. Join us in discovering the chemical reactions that occur in the upcoming program.