Give reasons for the following –
a) Why is sodium kept immersed in kerosene oil?
b) Why calcium metal after reaction with water starts floating on it?
c) Why plaster of Paris should be stored in a moisture proof container?
d) Why is baking soda used as an antacid?
e) Why does an aqueous solution of acid conduct electricity?
Give reasons for the following –
a) Why is sodium kept immersed in kerosene oil?
b) Why calcium metal after reaction with water starts floating on it?
c) Why plaster of Paris should be stored in a moisture proof container?
d) Why is baking soda used as an antacid?
e) Why does an aqueous solution of acid conduct electricity?
a) Sodium reacts so vigorously with air that they catch fire if kept in the open. Hence, to protect them and to prevent accidental fires, they are kept immersed in kerosene oil.
b) The reaction of calcium with water is less violent. The heat evolved is not sufficient for the hydrogen (evolved due to the reaction) to catch fire. Calcium starts floating because the bubbles of hydrogen gas formed stick to the surface of the metal.
c) The Plaster of Paris should be stored in a moisture-proof container as it absorbs water from moisture and turns into hard Gypsum. It’s difficult to get back Plaster of Paris from Gypsum.
d) Antacids are bases which neutralize the excess acid produced inside the stomach. Baking soda (NaHCO3) is also a base so it can neutralize the excess acid. Hence, it is used as antacid.
e) The presence of hydrogen (H+) or hydronium (H3O+) ions in the aqueous solution of an acid are responsible for conducting electricity.
a) Sodium reacts so vigorously with air that they catch fire if kept in the open. Hence, to protect them and to prevent accidental fires, they are kept immersed in kerosene oil.
b) The reaction of calcium with water is less violent. The heat evolved is not sufficient for the hydrogen (evolved due to the reaction) to catch fire. Calcium starts floating because the bubbles of hydrogen gas formed stick to the surface of the metal.
c) The Plaster of Paris should be stored in a moisture-proof container as it absorbs water from moisture and turns into hard Gypsum. It’s difficult to get back Plaster of Paris from Gypsum.
d) Antacids are bases which neutralize the excess acid produced inside the stomach. Baking soda (NaHCO3) is also a base so it can neutralize the excess acid. Hence, it is used as antacid.
e) The presence of hydrogen (H+) or hydronium (H3O+) ions in the aqueous solution of an acid are responsible for conducting electricity.
