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 […]
Why should a magnesium ribbon be cleaned before burning in air? Read More »
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