Acid rain is rain that is usually acidic due to the presence of sulphuric acid and nitric acid along with rain water. It is caused when harmful gases like sulphur dioxide and nitrogen oxides are released into the atmosphere which mix with water vapours and oxygen and fall down in the form of acid rain. It is defined as rain water having pH less than 5.6 and is harmful for living organisms.

For the given property, place a tick ✓ in the correct column. Property Acid Base Identified using indicators

Property Acid Base Identified using indicators ✓ ✓ The substances which assist in determining whether the given substance is acidic or basic, with the help of a colour change, are called indicators. Turmeric, China rose and litmus a re some naturally used acid-base indicators.

For the given property, place a tick ✓ in the correct column. Property Acid Base Feels soapy to the touch

Property Acid Base Feels soapy to the touch ✓ Bases are bitter to taste, turn red litmus to blue and are slippery to touch.

For the given property, place a tick ✓ in the correct column. Property Acid Base Sour in taste

Property Acid Base Sour in taste ✓ The substances that contain acids are known as acidic substances. The word 'acid' comes from the Latin word 'acere' meaning sour. Some substances like orange, curd and tamarind have a sour taste.

For the given property, place a tick ✓ in the correct column. Property Acid Base May be corrosive

Property Acid Base May be corrosive ✓ ✓ A corrosive substance is defined as a material capable of damaging or destroying other substances on contact via a chemical reaction. Strong acids and strong bases are corrosive in nature.