Acids are proton donors in chemical reactions which increase the number of hydrogen ions in a solution while bases are proton acceptors in reactions which reduce the number of hydrogen ions in a solution. Therefore, an acidic solution has more hydrogen ions than a basic solution; and basic solution has more hydroxide ions than an acidic solution. Acid substances taste sour. They have a pH lower than 7 and turns blue litmus paper into red. Meanwhile, bases are slippery and taste bitter. Its pH is greater than 7 and turns red litmus paper into blue. Acid- base neutralization is done by adding an acid to a base or a base to an acid until the substance has equal hydrogen and hydroxide ions. This is used to determine unknown concentration of a …show more content…
Procedure A. Preparation of NaOH solution The molarity of a solution is the ratio of the number of solutes dissolved in a liter of solution. To figure out the needed mass (in grams) of NaOH pellets to be dissolved in a 0.25 L of water, remember that a mole is equivalent to the quotient of mass over the molar mass of the substance. This was used to rearrange the base formula and to derive the mathematical equation of mass in terms of molarity. mass (g) = (Molarity)(Volume)(Molar mass) The pellets were dissolved thoroughly then was used in filling up the 100 mL volumetric flask. The solution was mixed well …show more content…
Standardization of NaOH solution The prepared solution in part A was used to determine the acidity of the two different brands of soft drinks. But before it, the NaOH solution was standardized first. A 0.15 g of potassium acid phthalate was dissolved in 0.05 L of water in an Erlenmeyer flask. Afterwards, 3 drops of phenolphthalein was added. A 50 mL buret was obtained and was washed with NaOH solution. After filling the buret with NaOH (titrant) and preparing the KHP (analyte) in the Erlenmeyer flask, the solutions were titrated. The volume used from the NaOH solution was recorded. C. Determination of the Acidity of Soft Drinks First, the soft drinks were heated. Upon cooling, it was shaken until no bubbles were formed. 20 mL of each brand of soft drinks was titrated with NaOH solution. 3 drops of phenolphthalein was used as an indicator if it has already completely reacted. The acidity can then be calculated referring on the known concentration and volume of base; and the known volume of acid. IV. Data and observations Mass of beaker (g) 174.01 Mass of beaker + NaOH pellets (g) 174.54 Mass of NaOH pellets 0.53 TRIAL 1 TRIAL 2 Mass of potassium acid phtalate (KHP) (g) 0.15 0.15 final buret reading (ml) 30.75