The correct option is [C]. Sodium carbonate decahydrate (Na₂CO₃·10H₂O), also called washing soda, is used to remove permanent hardness of water. It reacts with calcium and magnesium salts, forming insoluble carbonates, softening the water effectively. Download cbse sample paper for class ...
Category: Class 10 Science
NCERT Solutions for Class 10 Science and important questions for CBSE class 10 for session 2020-2021
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The correct option is [C]. When zinc granules react with sulphuric acid (X), zinc sulphate (ZnSO₄) forms and hydrogen gas (Y) is released. The hydrogen gas burns with a pop sound near a candle, confirming its identity. Tiwari Academy provides CBSE ...
The correct option is [B]. Sodium hydroxide is called an alkali because it is a base that dissolves in water, forming a basic solution. Ferric hydroxide, though a base, is insoluble in water and not termed an alkali. class 10 science ...
The correct observation is (a). In test tube P, zinc displaces copper from copper sulphate, forming a red-brown copper layer on the strip. In test tube Q, no reaction occurs as zinc cannot displace magnesium from magnesium sulphate. class 10 science ...
When a piece of magnesium ribbon is ignited, light and heat are produced. Magnesium ribbon on burning in air is an exothermic reaction. correct option is (c). CBSE Sample Paper Class 10 Science 2025-26 Download cbse sample paper for class 10 science