Sodium carbonate, also known as soda ash, forms a medium-strength base when in a solution of water. Depending on the amount of sodium carbonate in the solution, the pH can range from around 11.3 to 11.7.
An acid is defined as an element that breaks apart in water to produce positively charged hydrogen (H+) ions, while a base reacts with water to form negatively charged hydroxide (OH-) ions. Acids are defined as anything with a pH below seven, while a base is any solution with a pH higher than seven. The pH scale runs from zero to 14, meaning sodium carbonate with a pH of just over 11 is only a medium-strength base