Introduction: The chemical reaction of nitration consists of a nitro group being added to or substituted in a molecule. Nitration can fundamentally be carried out by a mixture of concentrated azotic acid and sulphuric acid ; this mixture is utile to obtain the active nitronium ion. Electrophilic aromatic permutation is a method used when a functional group is needed to be substituted on to an aromatic compound. In the nitration. nitronium ion Acts of the Apostless as the electrophile that involves the onslaught of the electron-rich benzine ring.
Aromatic permutation is electrophilic. due to the high denseness in benzine ring. Benzene ring is one of the constituents in most of import natural merchandises and other utile merchandises. The species responding with the aromatic ring is normally a positive ion or the terminal of a dipole. Nitration is one of the most of import illustrations of electrophilic permutation. The electrophile in nitration is the nitronium ion which is generated from azotic acid by protonation and loss of H2O. utilizing sulphuric acid as the dehydrating agents. Datas:
Weight ( gms )
39. 1 gms
Beaker + Crystals
41. 9 gms
Weight of Crystals ( Prior to Addition of Ethanol )
2. 8 gms
Figure 1: This tabular array illustrates the weight of the crystals that were formed before the ethyl alcohol was added. 2. 8 gms x 5= 14 milliliter
– This is the sum of ethyl alcohol that is needed to merely fade out the bromonitrobenzenes at 78. 2oC.
Weight ( gms )
Wet Sample of Crystals
1. 40 gms
Dry Sample of Crystals
0. 95 gms
Difference Between Wet and Dry Samples
0. 45 gms
Figure 2: This tabular array illustrates the weight of the crystals that were formed as the concluding merchandise. The wet sample and dry sample both have a different value.
Figure 3: This is the construction of bromobenzene ; this was the liquid that was given for this laboratory experiment.
Figure 4: Mechanism for the formation of 4-bromonitrobenzene.
Observations: When the bromobenzene was added. the solution turned xanthous. The concluding merchandise was besides xanthous crystals.
0. 0142 mol bromobenzene
b. Nitric Acid
0. 090 mol azotic acid
Therefore. IT CAN BE SAID THAT BROMOBENZENE IS THE LIMITING REAGENT
c. Actual Yield and Percent Yield
THE PERCENT YIELD IS 33 % .
Decision: It can be said that the aim of this experiment was to synthesise the p-bromonitrobenzene out of bromobenzene by nitration. This
experiment studied the electrophilic aromatic nitration of a monosubstituted aromatic cring under a standard set of conditions. Electrophilic aromatic permutation is the add-on of a nitro ( NO2+ ) group to an aromatic ring. When the aromatic ring is monosubstituted ( intending it already has one substituent on it ) . the nitro group can be added to either the: ortho. meta. or para place. Figure 1 illustrates the weight of the crystals prior to the add-on of ethyl alcohol. The weight of the crystals before the ethyl alcohol was added was 2. 8 gms. These were the crystals that were formed when the azotic acid and sulphuric acid mixture was easy added to the bromobenzene. The weights of the crystals were determined before the add-on of ethyl alcohol ; this was of import to make in order to happen the sum ( milliliter ) of ethyl alcohol to add. The weight of the crystals was 2. 8 gms and was multiplied by 5 to acquire 14mL ; this was the sum of ethyl alcohol that was added. The ethyl alcohol was added to the crystals to fade out the bromonitrobenzenes at 78. 2oC. Figure 2 illustrates the weight of the moisture crystals and the dry crystals. The weight of the moisture crystals was 1. 40 gms and the weight of the dry crystals was 0. 95 gms.
The difference between these two weights was 0. 45 gms. The figure for the dry crystal was so subsequently used to find the existent output and the percent output of the laboratory experiment. . The moles of bromobenzene were calculated to be 0. 0142 moles. The moles of azotic acid were calculated to be 0. 090 moles. Therefore. since the moles of bromobenzene were lower than the moles of azotic acid. it can be said that bromobenzene is the confining reagent. After the confining reagent is found. it is used to happen the theoretical reagent.
1. What merchandises did you anticipate this reaction to organize? Explain the consequence that the group ( s ) nowadays in the get downing stuff have on responsiveness and orientation in this reaction and why.
There were two possible merchandises that could hold been formed in this experiment. The first merchandise that could hold formed was 1-bromo-2-nitrobenzene and the 2nd merchandise that could hold formed was 1-bromo-4-nitrobenzene. These were the two merchandises that could hold been formed because Br is in an ortho and parity directing group.