Red Cabbage Indicator Prac Write Up
Red Cabbage Indicator Experiment
Aim: The aim of our investigation was to identify and understand how different chemicals (Acids, alkalis and neutral) react and experience a change in colour due of this.
Introduction:
The red cabbage indicator shows how a usual household product such as red cabbage can make a suitable indicator and be able find out if a chemical is either and acid, alkali or neutral. Acids are a chemical that reacts with an alkali neutralising it producing water and a salt. Acids are also commonly found to be sour tasting. Acids react with metals, releasing hydrogen gas and leaving behind a salt they also can conduct electricity. Acids also readily give off hydrogen ions and have a pH level lower than 7. Some more common laboratory acids are Hydrochloric, Sulphuric and Nitric Acids. Sulphuric acids and water are used in car batteries as the electrolyte.
Bases or alkali are a chemical that will react with acids and usually have a slimy or soapy feeling on contact with skin. Bases readily accept hydrogen ions and has a pH level that is higher the 7. Bases have a bitter taste and neutralise d by acids, producing water and a salt. Some common laboratory bases are Sodium Hydroxide, Potassium Hydroxide and Calcium Hydroxide. Stronger bases are commonly used today in many cleaning products.
Indicators help us find wether if a chemical is an acid or base. The scale that is used to find wether a chemical is an acid or a base is the pH scale. The pH scale gives us an indication of the amount of hydrogen ions and goes from 1 – 14, one being the strongest acid and 14 being the strongest base. Many plants and flowers have natural substances which have indicating properties that allow them to be used as indicators. The red colour of red cabbage comes from a molecule called an anthocyanin. Very acidic solutions will turn anthocyanin a red colour. Neutral solutions result in a purplish colour. Alkalis solutions appear in greenish-yellow.
Aim: The aim of our investigation was to identify and understand how different chemicals (Acids, alkalis and neutral) react and experience a change in colour due of this.
Introduction:
The red cabbage indicator shows how a usual household product such as red cabbage can make a suitable indicator and be able find out if a chemical is either and acid, alkali or neutral. Acids are a chemical that reacts with an alkali neutralising it producing water and a salt. Acids are also commonly found to be sour tasting. Acids react with metals, releasing hydrogen gas and leaving behind a salt they also can conduct electricity. Acids also readily give off hydrogen ions and have a pH level lower than 7. Some more common laboratory acids are Hydrochloric, Sulphuric and Nitric Acids. Sulphuric acids and water are used in car batteries as the electrolyte.
Bases or alkali are a chemical that will react with acids and usually have a slimy or soapy feeling on contact with skin. Bases readily accept hydrogen ions and has a pH level that is higher the 7. Bases have a bitter taste and neutralise d by acids, producing water and a salt. Some common laboratory bases are Sodium Hydroxide, Potassium Hydroxide and Calcium Hydroxide. Stronger bases are commonly used today in many cleaning products.
Indicators help us find wether if a chemical is an acid or base. The scale that is used to find wether a chemical is an acid or a base is the pH scale. The pH scale gives us an indication of the amount of hydrogen ions and goes from 1 – 14, one being the strongest acid and 14 being the strongest base. Many plants and flowers have natural substances which have indicating properties that allow them to be used as indicators. The red colour of red cabbage comes from a molecule called an anthocyanin. Very acidic solutions will turn anthocyanin a red colour. Neutral solutions result in a purplish colour. Alkalis solutions appear in greenish-yellow.