Here's why:

* Soap is made through saponification: This process involves reacting a fat or oil with a strong alkali (like lye or potassium hydroxide). The resulting soap molecules have a polar (water-loving) head and a non-polar (oil-loving) tail.

* Alkalinity helps with cleaning: The alkalinity of soap allows it to break down grease and dirt, which are often acidic.

* pH of soap: While the exact pH varies, hand soap is generally between 9 and 10, which is considered alkaline.

However, it's important to note:

* There are some hand soaps that are closer to neutral (pH 7), particularly those marketed as "gentle" or "for sensitive skin."

* The pH of soap can also be influenced by other ingredients added during the manufacturing process.

Therefore, while hand soap is generally alkaline, there is some variability depending on the specific product.