Okay kiddo, let me explain the azo coupling in a very simple way. The azo coupling is like making two friends and introducing them to each other. Let me explain more.
So imagine you have two colors of play-dough - blue and yellow. Now, let's say you want to make a new color, orange. One way of doing this is by mixing blue and yellow play-dough together, but there is another way - by introducing them to each other by making them into little balls and squishing them together!
Now let's go back to the azo coupling. Azo compounds are molecules with a special group made up of two nitrogen atoms, called -N=N-. These nitrogen atoms are like the little balls in our play-dough example.
When two azo compounds are introduced to each other, under the right conditions, these little balls (-N=N-) can link together to form a long chain. This process of linking the two azo compounds is called azo coupling. Just like how we squished the blue and yellow play-dough together to make orange, the two azo compounds are squished together to make a new molecule.
One important thing to note is that the conditions have to be just right for azo coupling to happen. Similar to how we need to squish the play-dough just right to get the perfect blend, scientists need to use the right temperature, pH, and other conditions to ensure that the azo coupling is successful.
So, that's azo coupling - it's like introducing two friends to each other to make a new molecule!