- make up the mark on the volumatric flask with de-ionised water. Stopper firmly, and shake the flask throughlyto mix the contents.
- label the flask clearly, with your name, the date, and the contents of the flask.
Risk assessment
Titration
Part 2
Titration is a common laboratory method of quantitative/ which can be used to determine the of a known . Because volume measurements play a key role in titration, it is also known as volumetric analysis. A , called the titrant, of known concentration (a ) and is used to react with a measured quantity of reactant (Analyte). Using a calibrated to add the titrant, it is possible to determine the exact amount that has been consumed when the endpoint is reached. The endpoint is the point at which the titration is stopped. This is classically a point at which the number of of titrant is equal to the number of moles of analyte. In the classic strong acid-strong base titration the endpoint of a titration is when the pH of the reactant is just about equal to 7, and often when the solution permanently changes color due to an .
After complating the standard solution experiment, we have to find the unkown subsnce by using the titration method.
Apparatus
- Pipette
- Pipette filler
- Burette
- Granduated flask
- Beaker
- Methole (organe)
- Hydrchloric acid
- Sodium carbonate
- Goggles
- Clamp
Method
- Place the clamp and make sure it is secure and stable, so it is vertical. Make sure yo uhave rinsed the portions blow the tap and tipped the washing away. This needs to be undertaken before rinsing with distilled water.
- Repeat this procedure; the reason for repeating being that this cleans the burette of any impuritites that may have accumulated when not in use.
- Obtain a beaker ( which has been rinsed twice with de-ionised water) and a white tile.
- Place the white tile under burette and then place the beaker on top of the white tile.
-
Next the burette casn be filled as close to 0.00 as possible. (make sure the tap is closed)
- Fill the pippette with de-ionised water to clean any impurities away.
- Using the pipette filler fill the pipette with your standard solutuion (sodium caronate) and pour it in the beaker.
- Pour a couple of drops of methyl (orange)
- open the for a few seconds at a time until the sandard solution changes from orange to pink.
- lastly read the measurments of the hydrochloric acid in the burette and record the amount left.
Burette:
The precision of a burette makes careful measurement with a burette very important to avoid . When reading a burette, the viewer's eyes must be at the level of the graduation to avoid error. Even the thickness of the lines printed on the burette matters; the bottom of the of the liquid should be touching the top of the line you wish to measure from. A common rule of thumb is to add 0.02 mL if the bottom of the meniscus is touching the bottom of the line. Due to the precision of the burette, even a single drop of liquid hanging from the bottom of a burette should be transferred to the receiving flask, usually by touching the drop to the side of the receiving flask and washing into the solution with the experimental (usually water). Through careful control of the stopcock and rinsing, even partial drops of liquid can be added to the receiving flask.
Pipette:
A pipette is a instrument used to transport a measured of . Pipettes are commonly used in and as well as tests. Pipettes come in several designs for various purposes with differing levels of , from single piece flexible plastic transfer pipettes to more complex adjustable or electronic pipettes. A pipette works by creating a above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid
Risk assessment
Results
This the resultes that I got from the titration test:
To find the mean of the main average you add up test 1, test 2, test 3, and then divid it by 3
Concultion:
All together I think the experiment went every well and my results came to be 1.040 mol/ dm
Evaluation:
I think my courework went very well but had same problems on the way, but I was able to over came it and get the results that I wanted.
The procedure went very well indeed. I can tell this because my results were very reliavle giving a nearly perfect results. I do not thing the procdure needs any changing if I had to do it again, as there is nothing I can see that needs improving.
I repeated my experiment three times, each set of my results very simlar. Genrally the results was not different by more than same mol/dm between them. This indicates that all my results are vey reliable overal. I also measured everything carefully using the burette and pipette.
Same of the problems that I faced was that the people that I was wok with which created same problem for and for the experiment. Also the other problems that I faced was tdue to the equipment was given to do the experiments. Same of the that was given equipments was not neeeded in the experiment and on the other hand there were equipment that was not given to us which slowed down the experiment. Other than that the experiment went very smoothly to the last minutes.
Background calculations:
Step 1: weigh the beaker with the Na CO and then weigh the beaker
Mass of beaker and Na CO = 36.60g
Mass of beaker = 35.20g
After getting the mass you take it away
36.60 – 35.20 = 1.40
Step 2: Find the RAM of Na CO
Na = 23 mulitply by 2
C = 12
O = 16 mulitply by 3 = 48
So you add 23 + 23 + 12 + 16 + 16 + 16 = 106
Step 3: to find the number of moles in Na CO you divide 1.40 by 106 which you get 0.0132 moles
Step 4: Next we find the concentration of Na CO soution you divide 0.01323 by 0. 025 which you get 0.0528 mol/dm
Step 5: I need to balance the equation
Na CO + 2HCl 2NaCl + CO +H O
Step 6: After finding the concentration of Na CO we need to find the number of moles. So you do
No of moles = concentration volume
= 0.0528 0.025 = 0.00132
Step 7: In addition, we had to find the number of moles of HCl. To find this
NO of moles of HCl = 0.00132 2
= 0.00262
Step 8:lastly you get the volume of HCl from the titration which is25.22, to give you final results
HCl concentration = moles divided by volume dm
0.00264 = 1.046 = 1.050 mol/ dm
0.002522
