Chemistry - Study Mode
[#566] Burning pyrites ore gives out
Correct Answer
(B) Sulphur dioxide gas
Explanation
Solution: The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS 2 . Pyrite remains in commercial use for the production of sulfur dioxide, for use in such applications as the paper industry, and in the manufacture of sulfuric acid.
[#567] Which one of the following pairs is not correctly matched?
Correct Answer
(A) Haematite : Copper
Explanation
Solution: Haematite : Copper is not correctly matched.
[#568] The common name of sodium bicarbonate is
Correct Answer
(B) Baking soda
Explanation
Solution: The common name of sodium bicarbonate is Baking soda.
[#569] Which among the following stage is suitable indicator when solution of sodium carbonate is mixed with sulphuric acid ?
Correct Answer
(D) Methyl orange
Explanation
Solution: Methyl orange is a pH indicator frequently used in titrations. It is often used in titrations because of its clear and distinct colour change. Because it changes colour at the pH of a mid-strength acid, it is usually used in titrations for acids. In a solution becoming less acidic, methyl orange moves from red to orange and finally to yellow with the reverse occurring for a solution increasing in acidity. The entire colour change occurs in acidic conditions. In an acid it is reddish and in alkali it is yellow
[#570] Alum stops bleeding in minor cuts because of
Correct Answer
(D) Coagulation
Explanation
Solution: Coagulation is the process by which blood forms clots. It is an important part of homeostasis, the cessation of blood loss from a damaged vessel, wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop bleeding and begin repair of the damaged vessel. Disorders of coagulation can lead to an increased risk of bleeding (hemorrhage) or obstructive clotting (thrombosis). Alum in block form (usually potassium alum) is used as a blood coagulant. Styptic pencils containing aluminium sulfate or potassium aluminium sulfate are used as astringents to prevent bleeding from small shaving cuts. For example, alum blocks are commonly sold in pharmacies in India.