An Introduction to titration: Standardization of HCl and NaOH
Objective & Background: The objective of this experiment is to determine the concentration of HCl (Hydrochloric acid) and NaOH (Sodium hydroxide) by carrying out a naturalization reaction between an acid solution and a base solution. To find the concentration of HCl you must weigh .15g of dried NaCO3, and dissolve it in 100mL of solution (water), after doing this add .5 to 1mL of bromocresol green indicator till it turns blue, next titrate it with HCl till green, then heat it to evaporate the CO2 back to blue and titrate it once again until yellow. After doing these steps calculate morality of HCl. To find the concentration of NaOH first weigh .5-.6 g of dried potassium hydrogen phthalate (KHPI), and dissolve it in 100mL boiled water. After cool it to room temperature and add 2-4 drops of phenolphthalein indicator. Then titrate it with NaOH until it turns into a pink color. After doing this calculate morality of a NaOH solution.
Chemical reaction:
1. 2HCl + Na2CO3 H2CO3 + 2NaCl
2. NaOH + HKC8H4O4 NaKC8H4O4 + H2O
Number of moles of HCl and NaOH when 0.15 g of Na2CO3 and .50 g of KHP are used
1. .15g Na2CO3 x [(1 mol Na2CO3) / (105.988 g Na2CO3)] x [(2 mol HCl)/(1 mol Na2CO3)] = .0028305 mol HCl or .0028 mol HCl
2. .50 g HKC8H4O4 x [(1 mol HKC8H4O4) / (204.2215 g HKC8H4O4)] x [(1mol NaOH) / (1 mol HKC8H4O4)] = .0024483 mol NaOH or .0024 mol NaOH