0“Chemistry is not only in the lab… it’s happening around you right now!”
Have you ever noticed these?
- Iron gate becoming reddish brown 🚪
- Cut apple turning brown 🍎
- Milk turning into curd 🥛
- Cake rising while baking 🎂
So lets get to knoww these!!
A chemical reaction is:
A process in which one or more substances change into new substances with different properties.
Example:
Paper burning 🔥
Paper + fire → ash + gasesCan we get the paper back? ❌ No
So a new substance formed.
🧠 How to Identify a Chemical Reaction?
1. Colour change 🎨
Example: Iron rusting
Iron = grey
Rust = reddish brown
Flowchart:
Iron + Oxygen + Moisture → Rust
Real-life scenario:
Why does an unused bicycle get rusted in rain? 🚲
Because water + air help iron react.
2. Change in temperature 🌡️
Some reactions release heat, some absorb it.
Exothermic reaction 🔥
Releases heat.
Example: Burning candle 🕯️
Wax + Oxygen → Carbon dioxide + Water + Heat
Comparison:
Like your phone heating while charging 📱
Endothermic reaction ❄️
Absorbs heat.
Example: Photosynthesis 🌱
Plants absorb sunlight to make food.
Carbon dioxide + Water + Sunlight → Glucose + Oxygen
Scenario:
Plants are basically tiny solar-powered food factories ☀️
3. Gas evolution 💨
Gas produced during reaction.
Example:
Vinegar + Baking soda → Carbon dioxide gas
Demo question:
Why do cakes become fluffy? 🎂
Because baking powder releases gas bubbles.
4. Formation of precipitate ☁️
An insoluble solid forms.
Example:
Milk curdling.
Another example:
Soap scum in hard water.
Think of it as:
Two clear liquids meet → suddenly solid appears!
Like surprise chemistry magic ✨
To know further something interest do book a class!!Will meet u there
