A STUDY OF AN UNKNOWN WEAK ACID Lab Report Example | Topics and Well Written Essays - 750 words

A STUDY OF AN UNKNOWN WEAK ACID - Lab Report fountA combination (pH-reference electrode) was obtained. A screw-like BNC connection of the electrode was inserted into the slot at the rear of the molar concentration and turned (unsteady or sporadic readings could indicate a loose connection).The electrode was susp reverseed from the meter arm and after which it was kept from drying verboten by placing it in a beaker of water. When it was ready to make measurements, the air hole under the knurl at the excrete was insured to be in the open position. The meter was then calibrated. The ATC probe was inserted in order to mechanically monitor the temperature. After this the electrode was rinsed with the wash bottle and blotted dry (the electrode was not rubbed as this would cause static buildup and monstrous results).For the case of the sample, a trial run was carried pop first to determine the required mass of noncitizen weak acid. For the trial run the sample need not be oven dry. A bout 0.1 g of the obscure sample was put into a 250mL beaker. The mass of sample taken for titration was adjusted, so that 30 to 40 mL of NaOH titrant was used to reach a pH of 10 or higher if no endpoint had been found. The rest unknown acid was heated in the 600C oven for approximately 1 hour before weighing out the next sample portions.When ready to titrate, about 100 mL of water was added to the previously weighed sample. The beaker was then located on the magnetic stirrer and stirred vigorously in order to dissolve. The electrode was immersed in the solution pickings care not to hit the fragile glass bulb with the stir bar. Then the burette was situated over the beaker. This was then titrated by adding 0.5 mL increments, recording to 2 decimal places, and reading the pH meter after each addition.A quick preliminary titration was performed in order to determine the location of the end point(s), carrying the titration past pH = 10 until no significant change in pH occurred wi th