BTEC Applied Science Unit 2 Assignment A - Titration
,BTEC Applied Science Unit 2 Assignment A - Titration
Unit 2 Assignment A Titration
Introduction
In this assignment I will be going through how I was able to find out an unknown concentration of a
solution using a standard solution to complete a titration. Once completing this I used a pH meter
and a colorimeter to find the unknown.
Calibration of pipette, balance and pH meter
Before starting the titration and making the standard solution, I firstly needed to calibrate a few
pieces of equipment: the pipette, balance and pH meter.
To calibrate the pipette, you firstly need to gather certain pieces of equipment including, a balance, a
small beaker, a larger beaker, thermometer, distilled water, a pipette and a pipette filler. You then
need to rinse all of your glassware with distilled water. Once you have completed the preparation
stage, you need to pour some distilled water into the large beaker and place a thermometer in with
the water and leave it until the water has reached room temperature (typically around 200C) then
record the temp. Next, place your empty small beaker onto a balance and record the mass shown.
Now take your pipette with the filler and fill it with water until the meniscus is at the line of the
pipette. Next, transfer the water into the smaller beaker you just weighed and record the mass of the
smaller beaker with the water. Repeat this process three times to ensure accuracy. When doing the
three trials, enter the data collected into a table that shows mass of beaker + water and mass of only
beaker. With the results you collected, work out the mean mass of water by taking the three masses
of water then divide by 3. You then need to calculate the volume of the pipette using the equation:
Volume = Mass x Z value. If the value you get from this equation is the same as the pipette volume,
this shows your pipette is calibrated.
To calibrate the balance used in the titration, you firstly need to gather your equipment including a
balance, a small screwdriver and a range of masses. In this method I will be using multiple 10g
masses as an example. To calibrate the balance, you firstly need to tare it then place your first 10g
mass onto the balance and observe the reading. If the reading is above or below the mass you have
added, use the screwdriver to adjust the values shown. Next add another 10g mass to the one
already on the balance and observe the value, again if the value shown is above or below the mass
you have placed, use the screwdriver to adjust the values. Repeat this with multiple masses to
ensure the balance is correctly calibrated. This is how you calibrate a balance.
To calibrate a pH meter, you firstly need to gather your equipment including a pH meter, a
screwdriver, three beakers, a solution with pH 4 and a solution of pH 9 and distilled water. Firstly,
pour pH 9 solution into a beaker, pH 7 solution into a beaker and distilled water into the third beaker.
Secondly, rinse the pH meter with distilled water then place it into the solution of pH 4 but be sure to
keep the meter levitated in the solution. Observe the numbers shown. If the number is below pH 4
use the screwdriver to adjust the values until it reaches pH 4. Do this for the pH 9 solution but make
sure to rinse the meter with distilled water in-between. Once you have completed these steps, rinse
the pH meter one more time and the pH meter is now calibrated.
, BTEC Applied Science Unit 2 Assignment A - Titration
How to carry out a standard Solution
Equipment list:
• Magnesium Carbonate
• Distilled water
• Weighing boat
• Digital balance
• Spatula
• Beaker
• Volumetric flask (250cm3)
• Funnel
• Glass rod
• Pipette
Method
To carry out the standard solution I firstly needed to calculate the mass of magnesium carbonate
solid that’s needed to produce 250cm3 of a 0.100 mol dm-3 solution by using the equation: Mass =
Moles x Mr. I then placed 4.2g of magnesium carbonate from the completed calculation into a dry
clean weighing boat that was already tared, using a spatula in small amounts to ensure I was
accurately adding the correct mass. Once the I reached 4.2g of magnesium carbonate I transferred it
into a beaker and added 100cm3 of distilled water. Next, I used a glass rod to stir the contents until all
the magnesium carbonate dissolved. I then used a funnel to transfer the contents of the beaker into
a 250cm3 volumetric flask and used more distilled water to wash the beaker and funnel into the
volumetric flask and kept adding distilled water until I reached 250cm3. Next, I plugged the end of the
volumetric flask and inverted it three times to make sure the added distilled water was mixed in with
the original dissolved solution. The standard solution was made.
Risk assessment
Risk Hazard Precaution Emergency
Could cause Magnesium -you must wear eye - if in the eye, flood
serious eye carbonate protection the eye with water
injuries/irritation for at least 10 mins
-Avoid touching eyes after and consult a medic
handling
-if swallowed, only
-avoid inhaling/ swallowing wash mouth with
the solid particles that may water and do not try
be released from the items to induce vomiting
packaging consult a medic
Glass could get Glassware -handle the glassware -if broken do not
broken/smashed; carefully touch the glass
glass could also -make sure to not be -if possible, swiftly
be stabbed into distracted while handling the clean up the broken
places such as glass glass with rubber
the hand gloves to avoid
further injury
Electrocution Electrical balance Do not touch any exposed If shocked, you
could happen or wires and make sure any should seek advice
electrical fires liquids are handled carefully from a medic and if a