UNIT 2 ASSIGNMENT A REPORTS 1-3
Report 1
, Introduc on:
What is a primary standard solu on? A primary standard solu on is a solu on which the
concentra on is known of accurately, the purity of a primary standard solu on should be
around 99.98%, The concentra on is usually stated as mol/dm3. Primary standard solu ons
are commonly used in tra ons and other analy cal chemistry techniques to determine an
unknown concentra on. Standardisa on of a solu on involves determining the
concentra on that is unknown within a substance.
Aim:
The aim of this prac cal was to prepare a primary standard solu on (Na2CO3).
Standardisa on of an acid and to trate the sodium carbonate to nd the unknown
concentra on within the substance.
Hypothesis:
If the sodium carbonate solu on changes from pink to colourless during tra on, this would
indicate the standardisa on of hydrochloric acid.
Method:
- The weighing scale had been calibrated.
- 1.36g of anhydrous sodium carbonate was weighed.
- The sodium carbonate was carefully transferred into a large beaker where
measurements were accurately and precisely taken so that an exact mass could be
transferred to the beaker
- 150cm3 of dis lled water would have been added to the beaker, this was s rred so
that the sodium carbonate was completely dissolved.
- All the solu on was carefully transferred into a 250cm3 volumetric ask. For the
solu on to reach 250cm3 more dis lled water was added to the volumetric ask.
- The pipe e was calibrated.
- 25cm3 of sodium carbonate was carefully transferred to a 250cm3 conical ask,
where a few drops of methyl orange indicator were added.
- A bure e was cleaned and lled with hydrochloric acid; the approximate
concentra on was 0.1M.
- The sodium carbonate solu on was trated with the hydrochloric acid. This was
done un l the indicator changed the colour at the end point.
- All measurements were accurately and precisely recorded so that the exact tre of
hydrochloric acid could be determined to reach the end point of the tra on.
Result/calcula ons:
- Mass of sodium carbonate = 1.36g
- Volume of solu on in volumetric ask = 25cm3 25/1000=0.025dm3
- RFM of Na2CO3 = 106
1.36
1 = 0.0128 m ol
106
ti tttitt
titititi tititi ti titi tifi ti titifltiti titi ti ti ti ti fifl ti tifltitifltiti ti
, 0.0128
1 = 0.0512 m ol /dm 3
0.025
Titra on table of results:
Rough Titra on 1 Titra on 2 Titra on 3
Final reading 13.50 15.50 15.50
Ini al reading 0.00 0.00 0.00
Titre volume 13.50 15.50 15.50
(13.50 + 15.50 + 15.50)
Average tre volume = = 14.8cm3
2
Discussion/conclusion:
We had prepared a primary standard solu on of Na2CO3 by weighing the solid using a
calibrated weighing balance, mixing and dissolving in pure water, and adjus ng the volume
of the solu on. The prepara on of the primary standard solu on enabled us to nd the
concentra on of sodium carbonate by using tra on.
From the table of results indicates that the average tre volume was 14.7cm3, this would
allow us to determine the accurate amount of needed to standardise hydrochloric acid. For
us to nd the unknown concentra on of sodium carbonate we had performed tra on to
nd the unknown concentra on by iden fying the change of colour from pink to colourless.
This helped to determine the concentra on.
Chemical hazards are a signi cant concern, and the likelihood of them occurring in
prac cal’s are somewhat high, precau ons would have to be taken to reduce the likelihood
of preventable accidents. Di erent chemicals come with their own set of risks. Sodium
hydroxide solu on in its powdered form brings up the risk of inhala on which can cause
chest ghtness or di culty in breathing.
Dilute sodium hydroxide is corrosive if brought in contact with the skin could cause serious
irrita on or severe burns, if dilute sodium hydroxide was accidentally rubbed into the eye, it
could cause burns in the eye which could possibly lead to permanent eye damage, if this was
to happen in the lab it would need to be washed out at the designated eye wash sta on to
prevent further damage.
Hydrochloric acid is corrosive to skin which could also cause serious irrita on and burns to
the skin, if hydrochloric acid was to accidentally spill and get into the eyes it would be
painful and can cause vision loss. To mi gate this risk, protec ve eye goggles should be worn
in the laboratory throughout the en re dura on of the prac cal. Since hydrochloric acid is
corrosive to the skin, gloves would have to be worn to reduce the risk of chemical burns.
Whilst handling chemicals it is important to understand the chemical hazard symbols, they
are printed on the bo le of the chemical so that the poten al risk of the chemical is made
fi ti titifiti tititi
ti ffitt ff
tifiti ti ti titititi ti titi ti ti titititi ti ti ti tifi titi
Report 1
, Introduc on:
What is a primary standard solu on? A primary standard solu on is a solu on which the
concentra on is known of accurately, the purity of a primary standard solu on should be
around 99.98%, The concentra on is usually stated as mol/dm3. Primary standard solu ons
are commonly used in tra ons and other analy cal chemistry techniques to determine an
unknown concentra on. Standardisa on of a solu on involves determining the
concentra on that is unknown within a substance.
Aim:
The aim of this prac cal was to prepare a primary standard solu on (Na2CO3).
Standardisa on of an acid and to trate the sodium carbonate to nd the unknown
concentra on within the substance.
Hypothesis:
If the sodium carbonate solu on changes from pink to colourless during tra on, this would
indicate the standardisa on of hydrochloric acid.
Method:
- The weighing scale had been calibrated.
- 1.36g of anhydrous sodium carbonate was weighed.
- The sodium carbonate was carefully transferred into a large beaker where
measurements were accurately and precisely taken so that an exact mass could be
transferred to the beaker
- 150cm3 of dis lled water would have been added to the beaker, this was s rred so
that the sodium carbonate was completely dissolved.
- All the solu on was carefully transferred into a 250cm3 volumetric ask. For the
solu on to reach 250cm3 more dis lled water was added to the volumetric ask.
- The pipe e was calibrated.
- 25cm3 of sodium carbonate was carefully transferred to a 250cm3 conical ask,
where a few drops of methyl orange indicator were added.
- A bure e was cleaned and lled with hydrochloric acid; the approximate
concentra on was 0.1M.
- The sodium carbonate solu on was trated with the hydrochloric acid. This was
done un l the indicator changed the colour at the end point.
- All measurements were accurately and precisely recorded so that the exact tre of
hydrochloric acid could be determined to reach the end point of the tra on.
Result/calcula ons:
- Mass of sodium carbonate = 1.36g
- Volume of solu on in volumetric ask = 25cm3 25/1000=0.025dm3
- RFM of Na2CO3 = 106
1.36
1 = 0.0128 m ol
106
ti tttitt
titititi tititi ti titi tifi ti titifltiti titi ti ti ti ti fifl ti tifltitifltiti ti
, 0.0128
1 = 0.0512 m ol /dm 3
0.025
Titra on table of results:
Rough Titra on 1 Titra on 2 Titra on 3
Final reading 13.50 15.50 15.50
Ini al reading 0.00 0.00 0.00
Titre volume 13.50 15.50 15.50
(13.50 + 15.50 + 15.50)
Average tre volume = = 14.8cm3
2
Discussion/conclusion:
We had prepared a primary standard solu on of Na2CO3 by weighing the solid using a
calibrated weighing balance, mixing and dissolving in pure water, and adjus ng the volume
of the solu on. The prepara on of the primary standard solu on enabled us to nd the
concentra on of sodium carbonate by using tra on.
From the table of results indicates that the average tre volume was 14.7cm3, this would
allow us to determine the accurate amount of needed to standardise hydrochloric acid. For
us to nd the unknown concentra on of sodium carbonate we had performed tra on to
nd the unknown concentra on by iden fying the change of colour from pink to colourless.
This helped to determine the concentra on.
Chemical hazards are a signi cant concern, and the likelihood of them occurring in
prac cal’s are somewhat high, precau ons would have to be taken to reduce the likelihood
of preventable accidents. Di erent chemicals come with their own set of risks. Sodium
hydroxide solu on in its powdered form brings up the risk of inhala on which can cause
chest ghtness or di culty in breathing.
Dilute sodium hydroxide is corrosive if brought in contact with the skin could cause serious
irrita on or severe burns, if dilute sodium hydroxide was accidentally rubbed into the eye, it
could cause burns in the eye which could possibly lead to permanent eye damage, if this was
to happen in the lab it would need to be washed out at the designated eye wash sta on to
prevent further damage.
Hydrochloric acid is corrosive to skin which could also cause serious irrita on and burns to
the skin, if hydrochloric acid was to accidentally spill and get into the eyes it would be
painful and can cause vision loss. To mi gate this risk, protec ve eye goggles should be worn
in the laboratory throughout the en re dura on of the prac cal. Since hydrochloric acid is
corrosive to the skin, gloves would have to be worn to reduce the risk of chemical burns.
Whilst handling chemicals it is important to understand the chemical hazard symbols, they
are printed on the bo le of the chemical so that the poten al risk of the chemical is made
fi ti titifiti tititi
ti ffitt ff
tifiti ti ti titititi ti titi ti ti titititi ti ti ti tifi titi
