Important Salts — Set 2
Chemistry · महत्वपूर्ण लवण · Questions 11–20 of 40
Which salt is used to remove the permanent hardness of water?
Correct Answer: C. Washing Soda
Washing soda reacts with soluble calcium and magnesium salts to form insoluble precipitates. This removal of metal ions makes the water 'soft' and suitable for lathering with soap. Its chemical formula is $Na_2CO_3 \cdot 10H_2O$.
Which salt is primarily responsible for the salinity of seawater?
Correct Answer: A. Sodium Chloride
Sodium Chloride accounts for the majority of the dissolved mineral content in ocean water. It is extracted through the evaporation of seawater in large salt pans. This salt is also the primary source of chlorine and sodium for industrial use.
What happens when baking soda is heated during the cooking process?
Correct Answer: D. Carbon dioxide is released
Heating baking soda causes thermal decomposition which produces carbon dioxide gas. This gas expansion creates the airy texture found in baked goods. Along with gas, sodium carbonate and water are also produced in this reaction.
Which salt is used as a supplement in common table salt to prevent goiter?
Correct Answer: D. Potassium Iodide
Potassium Iodide is added to salt to ensure the thyroid gland receives sufficient iodine. Goiter is a condition caused by iodine deficiency in the daily diet. Fortifying salt is a common public health measure worldwide.
Which salt is produced when Copper oxide reacts with dilute Hydrochloric acid?
Correct Answer: A. Copper Chloride
Copper Chloride is formed as a result of the neutralization between the metallic oxide and the acid. The solution turns a blue-green color during this specific chemical reaction. This is a standard example of an oxide-acid reaction.
The salt 'Epsom Salt', used for medicinal baths and as a fertilizer, is chemically?
Correct Answer: C. Magnesium Sulfate
Magnesium Sulfate is the chemical name for Epsom salt, named after a town in England. It is used to soothe sore muscles and provide essential magnesium to plants. In its heptahydrate form, it contains seven molecules of water of crystallization.
Which salt is used for making soda-acid fire extinguishers?
Correct Answer: B. Sodium Bicarbonate
Sodium Bicarbonate reacts with sulfuric acid in the extinguisher to produce a huge volume of carbon dioxide. The carbon dioxide gas effectively cuts off the oxygen supply to the fire. This is a classic application of gas-producing salts in safety equipment.
What is the common name of the salt Calcium Oxychloride?
Correct Answer: D. Bleaching Powder
Bleaching Powder is the common name for Calcium Oxychloride, produced by the action of chlorine on dry slaked lime. It is used as a disinfectant and for bleaching textiles. Its chemical formula is $CaOCl_2$.
Which salt is used in the manufacture of fireworks to produce a green color?
Correct Answer: B. Barium Salt
Barium salts are used in pyrotechnics specifically to emit a characteristic green flame. Different metal salts are chosen for fireworks based on the specific colors they produce upon heating. For instance, strontium salts are used for red and copper for blue.
Which of the following is a 'Double Salt'?
Correct Answer: A. Potash Alum
Potash Alum is a double salt because it contains two different cations in a fixed ratio. It crystallizes as a single substance but dissociates into its constituent simple ions in water. The formula for this specific double salt is $K_2SO_4 \cdot Al_2(SO_4)_3 \cdot 24H_2O$.