Give scientific reasons:
(1) Grills of doors and windows are always painted before they are used.
(2) Physical states of reactants and products are mentioned while writing a chemical equation.
(3) Potassium Ferrocyanide is stored in dark coloured bottles and kept away from sunlight.
(4) Iron articles rust readily whereas steel which is also mainly made of iron will not undergo corrosion.
(5) Edible oil is not allowed to stand for a long time in an iron or tin container.
Give scientific reasons:
(1) Grills of doors and windows are always painted before they are used.
(2) Physical states of reactants and products are mentioned while writing a chemical equation.
(3) Potassium Ferrocyanide is stored in dark coloured bottles and kept away from sunlight.
(4) Iron articles rust readily whereas steel which is also mainly made of iron will not undergo corrosion.
(5) Edible oil is not allowed to stand for a long time in an iron or tin container.
(1) As the grills of doors and windows are made up of iron, they easily catch rust on reaction with air and moisture present in the atmosphere. Hence, grills of doors and windows are always painted in order to prevent them from rusting.
(2) The reactants and the products given in the chemical equation may be in solid, liquid or gaseous states. A chemical equation makes use of chemical symbols to give a short statement of the chemical changes. Hence, to make the chemical equation more informative, physical states of the reactants and the products are mentioned in the chemical equation.
(3) Potassium ferrocyanide gets decomposed when exposed to bright light. The dark colour of the bottles absorbs a lot of energy from the light passing through it. So, potassium ferrocyanide is stored in dark−coloured bottles and is kept away from sunlight to prevent its decomposition.
(4) Stainless steel is an alloy of iron and chromium. Chromium reacts with oxygen and forms a very thin and stable corrosion product film on the surface of steel. This film acts as a barrier that limits oxygen and water to react with underlying material and prevents further corrosion.
(5) If edible oil is allowed to stand for a long time in an iron or tin container, the fatty acids in the oil react with iron or rust and form salts. These salts contaminate the oil and hence the oil becomes rancid.
(1) As the grills of doors and windows are made up of iron, they easily catch rust on reaction with air and moisture present in the atmosphere. Hence, grills of doors and windows are always painted in order to prevent them from rusting.
(2) The reactants and the products given in the chemical equation may be in solid, liquid or gaseous states. A chemical equation makes use of chemical symbols to give a short statement of the chemical changes. Hence, to make the chemical equation more informative, physical states of the reactants and the products are mentioned in the chemical equation.
(3) Potassium ferrocyanide gets decomposed when exposed to bright light. The dark colour of the bottles absorbs a lot of energy from the light passing through it. So, potassium ferrocyanide is stored in dark−coloured bottles and is kept away from sunlight to prevent its decomposition.
(4) Stainless steel is an alloy of iron and chromium. Chromium reacts with oxygen and forms a very thin and stable corrosion product film on the surface of steel. This film acts as a barrier that limits oxygen and water to react with underlying material and prevents further corrosion.
(5) If edible oil is allowed to stand for a long time in an iron or tin container, the fatty acids in the oil react with iron or rust and form salts. These salts contaminate the oil and hence the oil becomes rancid.
