Q. While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid? When you’re diluting an acid, you should always add acid to water because it’s safer. If you add water to acid, it can react very quickly and splash out, which could be […]
A: When a solution of Sodium Hydrocarbonate (NaHCO3), also known as Baking Soda, is heated: Decomposition Reaction: 2NaHCO3 → Na2CO3 + H2O + CO2 What happens: Sodium Hydrocarbonate breaks down into: Sodium Carbonate (Na2CO3) Water (H2O) Carbon Dioxide (CO2) Observations: Effervescence (bubbling) due to CO2 release Formation of a solid precipitate (Na2CO3) Practical Applications: Baking:
A: The sodium compound commonly used for softening hard water is Sodium Carbonate (Na2CO3), also known as Washing Soda. Sodium Carbonate removes calcium and magnesium ions, which cause water hardness, through a process called precipitation: Ca2+ + Na2CO3 → CaCO3 (precipitate) + 2Na+ Mg2+ + Na2CO3 → MgCO3 (precipitate) + 2Na+ This reaction forms insoluble
Name the sodium compound which is used for softening hard water. Read More »
A: The substance that yields bleaching powder (CaOCl2) when treated with chlorine is Calcium Hydroxide (Ca(OH)2). Chemical Reaction: Ca(OH)2 + Cl2 → CaOCl2 + H2O This question belongs to the first chapter of the CBSE 10th Std Science book: Acids, Bases and Salts Buy the Book
Name the substance which on treatment with chlorine yields bleaching powder. Read More »
A: The common name of the compound CaOCl₂ is Bleaching Powder. Bleaching Powder, also known as Calcium Hypochlorite, is widely used: As a disinfectant and sanitizer in water treatment and swimming pools. As a bleaching agent in laundry and textile industries. To kill bacteria, viruses, and other microorganisms. In households, Bleaching Powder is often used
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A: When magnesium ribbon is stored, it reacts with the oxygen in the air and forms a thin layer of magnesium oxide on its surface. This oxide layer prevents the magnesium from burning properly. Cleaning the ribbon with sandpaper removes this layer, allowing the magnesium to react fully with oxygen and burn brightly. This question
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A: Exothermic reactions release heat, like a warm campfire. Examples include burning wood or the reaction between baking soda and vinegar. Endothermic reactions absorb heat, making their surroundings cooler, like how an ice pack gets cold when you activate it. An example is when barium hydroxide mixes with ammonium thiocyanate. This question belongs to the
What does one mean by exothermic and endothermic reactions? Give examples. Read More »
The Magical Reaction: Remember our underwater adventure with the mug, electrodes, and bubbles? Well, it’s all about splitting water (H₂O) into its two best friends: hydrogen (H₂) and oxygen (O₂). The magical equation is: 2H2O→2H2+O2 For every two water molecules, we get one oxygen molecule and two hydrogen molecules. The Gas Mystery: The test tube
A: (i) The substance ‘X’ used for white washing is Quicklime or Calcium Oxide, and its chemical formula is CaO. (ii) When Calcium Oxide (CaO) reacts with water (H2O), it forms Calcium Hydroxide (Ca(OH)2). The reaction is as follows: CaO+H2O→Ca(OH)2 This is called the slaking of lime and the product, Calcium Hydroxide, is used for