How are the following substances classified into three groups with the help of litmus? Lemon, tamarind, baking soda, buttermilk, vinegar, orange, milk, lime, tomato, milk of magnesia, water, alum.

Answer the following questions: Classify aqueous solutions of the following substances according to their pH into three groups: 7, more than 7, less than 7. Common salt, sodium acetae, hydrochloric acid, carbon dioxide, potassium bromide, calcium hydroxide, ammonium chloride, vinegar, sodium carbonate, ammonium, sulphur dioxide.

Answer the following question : Classify the following into homogeneous solution and heterogeneous solution: Soda water, potassium permanganate solution, milk, alcohol in water, ink solution, wheat flour in water.