Analysis of Brick Cleaner Essay

Aim To find the percentage by mass of hydrochloric acid present in brick cleaner by doing an acid-base titration.Theory/Hypothesis The main ingredient in brick cleaner is HCL and must be diluted and titrated with a base to be equal to analyse it. It reacts with parts of the concrete which allows it to remove the concrete from the bricks. I think there leave be around 30% of HCL in brick cleaner.Materials* 5mL brick cleaner* 100mL, 0.1M standardised sodium carbonate stem* 250ml de-ionised water* Methyl orange indicator* 250mL volumetric flask* 4x100mL conical flasks* Small funnel* 10mL measuring cylinder* 20mL pipette* Pipette filter* Dropping pipette* Burette and stand* White tile* Electronic balance* Safety glasses* GlovesMethod1) A 250 mL volumetric flask was weighed with its mass recorded2) A 10mL measuring cylinder was used to pour 5mL brick cleaner into the volumetric flask. The flask was stoppered square(a) after all the brick cleaner was in the flask.3) The flask was th en reweighed4) De-ionised water was added until the flask was about half full. The flask was stoppered and shaken carefully top side down several times.5) More water was added to the flask about a cm below the graduation line. A holdper was used to accurately drop the right amount of water to the flask so the bottom of the meniscus was on the graduation line.6) A 20mL pipette was used to put 20mL of sodium carbonate theme into each of the four 100mL conical flask. 3 drops of methyl orange indicator was added to each.7) The burette was filled with the dissolving agent of brick cleaner.8) The sodium carbonate solution was titrated with the solution of brick cleaner until there was a clear permanent colour change.9) Steps 7 and 8 were repeated until 3 concordant results wereResultsWeightVolumetric flask78.968gBrick cleaner6.00gTitre123Initial vol2.323.43.0Final vol23.444.524.0Vol added21.121.121.0CalculationsOn page attached.DiscussionThe weight for the brick cleaner may not be 6.0 0g as the volumetric flask was not weighed again with the brick cleaner in it because that step was forgotten. So the result above was taken from another student that did the prac. This will affect the results as the mass of the brick cleaner is used to determine the percentage by mass of HCL in brick cleaner. All 3 titres show that they are that within 0.1 of each other. The hypothesis has been disproved because it was suggested the 30% of HCL would be in brick cleaner and theres only 2.4% although its not certain that those steps were through correctly. There were no problems encountered during this prac.Focus Questions8)a) the manufacturer says that brick cleaner is made up of around 35% HCL, which is a massive difference to the answer that was got in this prac but again question 7 was not done correctly.b) differences in class results occur because not everybody would have done the exact volume of brick cleaner, sodium carbonate etc as each other therefore the difference in re sults obtained.9) To correctly clean up a spill of 20mL brick cleaner you would mop it up immediately, dry wash it away with massive amounts of water10)a) volumetric flask= once with water twice with brick cleanerb) Burette= once with water twice with diluted solution of brick cleanerc) pipette= once with water twice with diluted brick cleanerd) conical flask=once with water twice with sodium carbonate solutionConclusion To conclude, there should be 35% HCL in brick cleaner although it was found that there was only 2.4%