1. Write the balanced chemical equation, total ionic equation and net ionic equations of the reaction. According to the chemical equation, what is the stoichiometric ratio of base to acid? 2. Calculate the average volume of base used to neutralize the acid. Using the average volume of base, calculate the unknown concentration of the acid. 3. What are the main sources of error in this experiment? What improvements can be made? 4. Explain how titrations can be used to monitor water quality. Any external references used need to be properly cited APA style. Trail 1 2 3 25.8 37.8 24.6 36.8 48.8 38.7 Intial buret reading(ml) Final buret reading(ml) Volume of HCI added (ml) 2.8ml 3.0ml 2.9ml A titration is an analytical procedure in which a solution of unknown concentration is combined with a known solution until a colour change is observed. The volumes of the two solutions are used to determine the amount of a particular chemical in the unknown solution. During this lab, an acid of unknown concentration (hydrochloric) will be titrated with sodium hydroxide solution, whose concentration is 0.5 mol/L. Pre-Lab 1. Read the entire procedure. 2. Make an observations table. 3. Answer analysis question 1. Safety Goggles must be worn at all times. Chemicals can be safely disposed of down the drain. Materials Erlenmeyer flask Burette Retort stand Burette clamp 10 mL graduated cylinder 100 mL beaker 50 mL beaker funnel Procedure 1. Ensure that all glassware is rinsed clean before proceeding. Fill the burette with tap water and then drain it through the stopcock. Do not remove the burette from the clamp. Fill it and drain it with a beaker. 2. Collect 70 mL of sodium hydroxide in the 100 mL beaker. 3. Fill the burette with sodium hydroxide solution being careful that the valve is shut (perpendicular) and that you do not overfill and spill the base. Open the valve to allow solution into the tip of the burette. 4. Record the volume of the base to the nearest 0.1 mL. 5. Into the 50 mL beaker, obtain about 20 mL of hydrochloric acid. 6. Using a graduated cylinder, measure 3.0 mL of hydrochloric acid; pour the acid into the Erlenmeyer flask; add five drops of phenolphthalein indicator to the acid. (If it turns pink, then pour the solution down the sink; rinse the flask well.) 7. Place the Erlenmeyer flask below the tip of the burette and open the valve. Swirl the flask continuously until the solution turns a permanent pink colour. At the endpoint, the solution will remain pink. The colour doesu't matter but even one drop can be the difference between the colour remaining pink. Use a white piece of paper as a backdrop to determine when you have reached the endpoint. Record the final volume in the burette. 8. Repeat the above steps with fresh HCl and phenolphthalein until you have three trials that are within 0.2 mL. 9. Allow the excess base to drain out. Fill the burette with water and drain. Store the burette upside down with the valve open. a