Which of the following is a property of alkaline solutions?

Alkaline solutions are characterized by the ability to neutralize acids, which is why the first statement is accurate. When an alkaline substance (like baking soda or ammonia) interacts with an acid, a chemical reaction occurs that results in the formation of water and a salt, effectively neutralizing the acidic properties. This characteristic is important in haircoloring and salon practices, as alkaline products are often used to open up the hair cuticle, allowing color to penetrate deeper and modify the hair’s pigmentation.

In terms of other properties mentioned, decreasing the pH level is characteristic of acidic solutions, not alkaline ones, since alkalis typically raise the pH level. Additionally, a sour taste is associated with acids rather than alkaline substances; alkalines are generally bitter. Finally, while alkaline solutions can indeed soften hair cuticles, this property relates more to their ability to swell the hair shaft rather than defining them as alkaline. Thus, the property of neutralizing acids accurately reflects the primary characteristic of alkaline solutions.