Ascorbic acid, a form of Vitamin C, is an essential nutrient found mainly in fruits and vegetables. Baking soda is a natural base compound. Acids are neutralized by bases, just like bases are neutralized by acids. Either compound can do damage to anything that is weak to it. For example, many acids will discolor or even destroy metal. Acids can damage skin or clothing as well, so knowing how to neutralize them can save you problems.
Identify the liquid as ascorbic acid; a stronger acidic material will not be neutralized by baking soda. Understand that you are dealing with an acid and a base. Acids and bases neutralize each other naturally.
Sprinkle baking soda onto the ascorbic acid. This will cause a reaction in which you will see some bubbling as the ascorbic acid and baking soda turn into carbon dioxide. You will notice that you are left with water and salt, after the bubbling subsides.
Clean up once the bubbling finishes. When all that's left is excess powder from the baking soda or a puddle of neutralized water, then it's safe to clean the area as normal. To clean, use a dry cloth to wipe away the powder and water. Follow up with a cleanser and another dry cloth to fully clean the area.