What is pH and why is alkalinity or acidity important for cleaning?

​What is pH and why is alkalinity or acidity important for cleaning?
The pH level of something tells us if it’s an acid or an alkaline. We know that pure water is 7.0, a completely neutral substance. You might recall from science in high school that the higher the pH number, the more alkaline it is, the lower the number, the more acidic it is. The more acidic or alkaline something is, the stronger it is, and the more reactive it will be (and potentially more dangerous to surfaces and humans).
Acids and alkalines can balance each other out; similar to hot and cold water. Boiling water can be made tepid by mixing with cold water. This is the same as an extremely acidic substance can be neutralised by adding the appropriate alkaline.
Why does pH matter for cleaning products?
Different cleaners work in different ways for different dirt. Most cleaners are alkaline, as the breakdown of dirt is most effective when the solution is alkaline.
Also, you don’t want to use a cleaner on a surface that will be damaged by the pH level. For instance, some delicate silks or wools will be damaged for acids or alkalines.
It’s also important to note so that you shouldn’t mix some cleaners. For instance, adding vinegar to bleach or ammonia will create extremely toxic and harmful gas.
What are acidic cleaners used for?
Acid cleaners include vinegar, lemon, and most detergents are slightly acidic. Acid is excellent to use on rust and other metal oxides. Hard water marks and mineral deposits on shower doors and soap scum are effectively treated with a mild acidic cleaner. However, acidic cleaners can damage surfaces, especially marble/ stone benchtops and other natural products.
What are alkaline cleaners best for?
Alkaline cleaners include ammonia, bleach, borax, and baking soda (this is why it reacts when paired with vinegar, which is acidic). Bars of soap are alkaline.
Alkalines work best with dirt such as grease, fats, and oils, which is why oven cleaners are often alkaline. Strong alkalines are great as drain cleaners as they dissolve grease, often the cause of blocked drains. Laundry powder is usually alkaline too, as it is effective in breaking down and removing natural body oils and proteins.