btec applied science full assignment (2022) new assignment , includes: all practicals and results from them chemical equations and working out evaluation, method, risk assessment, etc. took me 12 hours to complete this assignment non copyright. this lab report gave me a distinction star
We have been given a few tasks that all relate to finding the concentration of a solution today.
We are going to be creating a standard solution, titrating with it, using a pH meter instead on
an indicator and using a colorimeter.
Task 1 (Standardisation of a solution)
Creating a solution with a known concentration.
Standardisation method:
To standardise our solution, I measured out 2.65 grams of sodium carbonate in a weighing
boat on a calibrated scale and then transferred the solid sodium carbonate to a beaker making
sure all of it had been transferred over by rinsing the weighing boat with distilled water and
pouring all the liquid into the beaker with the sodium carbonate. I then mixed the sodium
carbonate with the distilled water and broke the sodium carbonate that had fused at the
bottom with my stirring rod. Once it was thoroughly mixed, I transferred the solution from
the beaker to a volumetric flask of 250 cm³ using a funnel and rinsed the beaker and funnel
well to ensure that the concentration of my standard solution remains what I want it to be. I
then filled up the volumetric flask until the meniscus of the solution was on the 250 cm³
mark, put a plug blocking the opening of the volumetric flask and inverted it to completely
mix the solution with the newly added distilled water.
Calculations:
1. Equation: Na2CO3 + 2HCL –> 2NaCl + H2O + C02
2. Concentration of Na2CO3 = 0.025/250 x 1000 = 0.1 moldm-3
3. Moles of Na2CO3 in 250cm-3 = 0.025, moles in 25cm-3 = 0.025/10 = 0.0025
Risk assessment:
Risk Hazard Level Precaution Emergency
Can cause Sodium Medium - Wear eye - Flood eye
serious eye Carbonate protection with water
irritation (anhydrous solid) - Avoid con- for 10mins
tact
Glassware Breaking/stabbin Low Handle carefully - If broken
g do not
touch.
Weighing Electrical shock Low Do not touch If shocked,
balance exposed seek medical
conductors advice.
Evaluation:
The standardisation we had to perform today was fairly straightforward, we mixed sodium
carbonate distilled water to form sodium hydroxide. While I feel my standardisation went
well, I could have set up and prepared for other titrations during this part.
, Task 2 (HCL and a standard solution)
We are aiming to find the concentration of hydrochloric acid using sodium carbonate
which with a known concentration and methyl orange as the indicator.
Equipment list:
1. Graduated pipette (25 cm³)
2. Funnel
3. Conical flask (250 cm³)
4. 3 beakers (preferably above 250
cm³)
5. Indicator
6. Clamp stand
7. Burette (50 cm³)
8. Pipette filler
9. Distilled water
Calibration of a scale:
I located the calibration button of the digital scale. The button may also be labelled as: “Cal,”
“Function,” “Mode,” or “Cal/Mode.” I pressed this button down until the digits displayed on
the scale turn to “0,” “000,” or “Cal.” I tested if it was calibrated and set it aside to use later.
Calibration of a volumetric flask:
To calibrate the volumetric flask, I placed the volumetric flask on a calibrated scale, recorded
the weight, and filled up the volumetric flask with 250cm³ of water. I took the weight of the
flask with water and subtracted it with the original weight and made sure the result was as
close to 250g as possible because the weight of a calibrated volumetric flask has to be as
close to its maximum value as possible.
Titration method:
I started out this titration by setting up a clamp stand filling two beakers, one with
hydrochloric acid and one with our standard solution which was sodium carbonate, rinsing
my burette with distilled water followed by sodium carbonate while keeping the tap open so
the whole burette is rinsed. I did the same with the pipette but rinsed it with hydrochloric acid
instead of the standard solution like the burette. After setting up the burette on the clamp
stand, I used the pipette filler and pipette to transfer 25cm³ of hydrochloric acid from my
beaker to the conical flask and added a few drops of indicator. I placed a funnel at the top of
the burette and filled up the burette with 50cm³ of sodium carbonate and took out the funnel
so any extra solution in the funnel doesn’t drip into the burette which would change results. I
then placed the conical flask under the burette and over a white tile. A white tile is used to
make any colour change or reaction easily visible.
Before starting the titration, I recorded the burette start volume in cm³ on my results table. I
kept swirling the conical flask while the sodium hydroxide and when I started to see a colour
change, I slowed down the flow of Na2CO3 into the conical flask. The colour change we are
looking is from an orange to very faint peach. After each titration, I recorded the burette end
volume and calculated the titre which is the difference between the burette start and end
volume. After rinsing all the equipment, I started out on the calculation of concentration. To
find out the concentration, I first balanced out the chemical equation, calculated the moles of
Na2CO3, calculated the molar ratio of HCL to Na2CO3 and then after changing all the volume
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