Acids and alkalis

• Neutral substances have pH values equal to 7
• Alkaline solutions have pH values greater than 7
• Acidic solutions have pH values less than 7
• Red cabbage indicator stays purple in the presence of a neutral solution. It turns pink in the presence of an acid and turns green/blue in an alkaline solution
• Litmus indicator turns red with an acid, blue with an alkali and stays purple if neutral
• Indicators are substances that change colour when acid or alkalis are added to it
• Each universal indicator colour is given it's own specific number called the Ph value. The Ph number tells us the strength of the solution. It says how strong or weak and how acid or alkali the solution