Which substance has a pH over 7?

A substance with a pH over 7 is considered basic or alkaline, which means it has fewer hydrogen ions compared to pure water, which has a neutral pH of 7. Baking soda, or sodium bicarbonate, is a well-known base with a pH typically around 8-9 when dissolved in water. This characteristic makes it useful for various applications, such as neutralizing acids and acting as a leavening agent in baking.

In contrast, vinegar and orange juice are both acidic substances with pH values below 7. Vinegar, primarily composed of acetic acid, has a pH range of about 2-3, while orange juice, which contains citric acid, typically has a pH around 3-4. Water, as mentioned earlier, is neutral with a pH of 7. Therefore, baking soda is the only option among the given choices that fits the criterion of having a pH over 7.