CPI: NITRATION

The Nitration reaction serves to introduce one or more ______ groups into a reacting molecule.

Nitro group

What is the formula of Nitrogen pentoxide?

N2O5

What is ” N2O4” called?

Nitrogen Tetroxide

Which is the most important Nitrating medium?

Nitric acid and Sulphuric acid

What is the formula of Nitrile ion?

NO2+

HNO3 + 2H2SO4 ——-> _____ + H3O+ 2HSO4-

NO2+

Doed nitric acid have different Ultraviolet spectrum?

Nitric acid has 3 different types of ultraviolet spectrums.

What is an Azide ion?

N3+

The 3 different Ultraviolet spectrum of nitric acid are dilute aqueous solvent, inert solvent and ester.

TRUE

What is the mixture of Nitric acid and Sulphuric acid called?

Mixed Acid

1\. ArH + ____ ——-> ArNO2 + H2O.

c) HNO3

2\. The nitrating agent is a/an ______ reactant.

The nitrating agent is called electrophile reactant as it is positively charged.

In which position does the nitro group enters?

Ortho, para, and meta are the positions on the ring where the Nitro group enters.

The electron density is least at which position?

The electron density is least at -meta position, as its least favourable position.

Nitration products at ortho and para position predominates? TRUE/FALSE

TRUE. As electron density is greater at ortho and para positions, the substitution of nitrating compound at ortho and para predominates.

What is alpha and beta position in naphthalene series?

Naphthalene series has 2 different mononitro derivatives called alpha and beta know as 1, 5 nitronaphthalene and 1, 8 nitronapthalene

The inductive effect is NOT associated with the dipole movement between the molecules C6H5-X? (TRUE/FALSE)

FALSE. The inductive effect depends on the electron density which produces a dipole movement between the molecule.

If X is negative in the inductive effect, it draws _____ towards itself.

ELECTRONS. The inductive effect is produced due to the movement of electrons as they are lighter. Therefore atoms or molecules having an electron induces negative inductive effect.

\-I effect causes _______ to electron?ATTRACTION/REPULSION

ATTRACTION. Inductive effect causes movement of electron -I effect attracts electron towards the molecule(X).

If X is the positive end of dipole, it will cause which effect?

POSITIVE (1+). As X is the positive end, it will increase the electron density on the ring and hence produces +I effect.

In -I effect, which position is most active?

META. -I effect reduces the reactivity of all the positions in the ring, and the effect being greater at ortho and para positions, hence meta is more active.

“NO2” produces which effect? (POSITIVE/NEGATIVE)

NEGATIVE (I-) NO2 is an example of -I effect as it causes reduction in reactivity.

If alkyl group increases, what happens to ortho: para ratio?

DECREASES. If alkyl group increases, the ortho substituted product decreases and ortho: para ratio decreases.

The inductive effect is weaker at ortho position than at para position.

FALSE. The inductive effect is stronger at ortho position than at para.

The rate of Nitration depends upon what?

TEMP. CONC. PRESSURE.

The kinetics of the nitration process depends upon what?

AROMATIC COMPOUNDS. With increase in aromatic compounds, the kinetics of nitration process increases.

Which order kinetics show highly reactive substrates?

ZERO ORDER

What do you mean by RDS?

a) Rate determining step \n b) Step on which the reaction depends \n c) It is the fastest step in the reaction

Is nitrosyl ion much weaker electrophile reagent than nitrile ion?

TRUE. Nitrosyl ion in NO+ whereas Nitrile ion in NO-, therefore nitrite ion is a stronger electrophile.

How many -NO2 groups are there in Picric acid?

THREE. Picric acid is also called 2, 4, 6- trinitrophenol and hence it contains three nitro groups.

ArH + (NO+) —-> _____ + (H+)

ArH + (NO+) —-> __**ArNO**__ + (H+)

The paraffinic are affected by the attack of ?

Free radical

The nitration in paraffinic produces ?

MONONITROPARAFFINS. The nitration process cannot produce any polynitro compounds hence we only get Mononitration paraffin’s.

What do you mean by Optimum temperature?

Optimum temperature is a __**temperature at which we get maximum yield**__ i.e maximum about of desired product.

How do we increase yield?

a) Getting optimum temperature \n b) Decreasing the activation energy \n c) Increasing the surface: volume ratio of reactor

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The above points increases the conversion rate of Nitric acid, hence the yield also increases.

What effect does Bromine has on yield and conversion of nitric acid to nitro paraffins? (BENEFICIAL OR NOT)

Bromine has a **beneficial effect** on yield and conversion of Nitric acid to Nitroparaffins, similarly Chlorine also effects the yield.

Reaction increases when Carbon chain becomes more branched. (TRUE/FALSE)

FALSE. The **rate of reaction decreases as carbon becomes more branched** as these branches cause hindrance to reactions.

The temperature coefficients for hydrogen substitution are in the order __primary > Secondary > Tertiary.__ (TRUE/FALSE)

TRUE. The rate of substitution in the reverse order at low temperature. As the reaction temperature is increased, the rates tend to approach equality.

What is an Alkyl radical?

a) -CH3 \n b) -C2H5 \n c) -C3H7

The Liquid phase nitration is of less importance than the gas phase nitration because of?

a) Low yield \n b) Lower conversion \n c) Occurrence of unwanted side reactions

2RCH2CH2 + NO2 ——–> HNO2 + **RCH=CH2** what is the name of this reaction?

Olefin (ALKENE) formation

What is RONO2 called?

RONO2 is called an **ester** because its “-C-O-” bond, attached to -NO2 group.

Which of the following is the nitrates of polyhydroxy compound which has an extensive use in propellants and explosives?

a) Glycerol \n b) Cellulose \n c) Pentaerythritol

What is the following structure called? \n R-N(-NO2)-R’

The following compound is named **nitramine** because the main chain ‘C’ atom is directly attached to ‘N’ group (nitrogen) and which is attached to -NO2 group.

What is the structure of Nitroamides?

RCO-N(-NO2)-R’

Primary nitramines cannot be prepared by the direct nitration of primary amines.

FALSE.

Which of the following is a Secondary nitramine?

a) R-N(-R)NO2 \n b) R-N-(-NO2)2 \n c) R3-N

R-N(-R)NO2. It is called secondary nitramine because two alkyl groups are attached to the ‘-N’ atom which is again attached to nitro group.

What is the name of the following compound? \n NH2-C(=NH)-NHNO2

The name of the compound is Nitro guanidine.

What is the fundamental difference between nitrate ester formation and nitration to form nitro compounds?

Nitrate ester is a **reversible process** whereas nitration to form nitro compounds is not.

Which of the following is a Nitrating agent? \n a) Nitrogen oxide \n b) Nitrogen dioxide \n c) Nitrogen trioxide

**Nitrogen dioxide** is a nitrating agent because it give two -NO2 groups which can be further used to for nitro paraffin’s compounds.

Is nitration reaction highly exothermic?

TRUE. huge amount of heat is liberated during nitration reaction therefore it is called exothermic

What is the denotion of enthalpy?

the enthalpy of reaction is denoted by H.

The total amount of heat lost by the reacting system from the start of the reaction till the products return to the initial temperature and pressure of the system, what is the heat ‘Q’ called?

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a) Heat of Formation \n b) Heat of reaction \n c) Heat of Nitration

ALL. Heat of nitration or heat of reaction or heat of formation ‘Q’ is an exothermic reaction, and it is the total amount of heat given out during nitration reaction.

Calculate the Heat of nitration

“Q”: C6H6 + HNO3 ——-> C6H5NO2 + H2O \n Qf: -9.7 kgcal +41.5kgcal—–> -2.3kgcal +68.4kgcal

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a) +34.3 kgcal \n b) -34.3 kgcal \n c) +43.3 kgcal \n d) -43.3 kgcal

Heat of nitration = product – reactant which is +34.3 kgcal.

The heats of nitration decrease with the increase in the number of nitro groups.

TRUE. The heat of nitration decreases as nitro group increases but heat of formation tends to increase till second and third group and diminishes thereafter.

Which of the following has the highest heat of formation? \n a) C6H5-NO2 \n b) C6H5-CH2-NO2 \n c) C6H5-NH-NO2 \n d) C6H5-N(-NO2)2

a. C6H5-NO2. It will have the highest amount of heat of formation because as -NO2 group increase it creates strain in molecules hence less amount of heat required the break the bond.

Which of the following compounds have high heat of formation?

(i) b-(2,3,4) trinitrotoluene

(ii) a-(2,4,6) trinitrotoluene .

\n a) (i) b-(2,3,4) trinitrotoluene \n b) (ii) a-(2,4,6) trinitrotoluene \n c) Both are equal \n d) Only (ii) a-(2,4,6) Dinitrotoluene

a-(2,4,6) trinitrotoluene has the highest heat of formation because it is quite stable without any stain within the molecules, and has low internal energy.

The heat of formation does not depends upon the internal energy of the molecule.

The heat of formation does depend upon the internal energy as, as the internal energy is high we get less amount of heat of formation.

Which is more Flexible batch process or continuous process equipment?

Batch process equipment

What size of equipment is needed in continuous process when compared with batch process?

SMALLER. Since it is not necessary to accumulate material in a continuous process anywhere, the vessels are designed with capacities dictated by the rate of the reaction process step which they must accommodate.

Which is safer Batch process or Continous process equipment?

Due to its relatively small size the **continous process** equipment has less material in it during processing hence it is safer than batch process.

Batch process is more efficient labour user than continuous process. (TRUE/FALSE)

FALSE. Since continuous processing minimizes the amounts of material in process on the average, it is often possible to handle operations at one place that require physical separation in a batch process and hence require additional labour.

What is/ are the major type of equipment for nitration processing?

BOTH BATCH/CONTINUOUS. For nitration processing we need both batch and continuous process, and depending upon other requirements we choose one of these processor.

What do we do in a reactor when its temperature become high and failure occurs?

We dump the content in a drowning tub and remove flumes through air outlet

What factors are of prime importance for the designing of a reactor?

a) Degree of agitation \n b) Control of temperature

Why do we need agitation in a reactor?

a) Efficiency \n b) For smooth reaction \n c) Avoid local overheating

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Agitation is needed to provide efficiency in reactor, even violent, to smooth reactions and also to avoid local overheating which could occur if stagnant spots were to exist in the nitrator.

Does wall jacket provide control of temperature in a reactor? TRUE/FALSE

TRUE. Wall jackets which are situated within the reactor walls contain coils in with water circulates.

What does “sleeve-and-propeller arrangement” in a reactor provides?

a) Good mixing \n b) Efficient heat transfer

Why is there a need to have one of the reactant in excess?

a) To achieve equilibrium faster \n b) Satisfying the stoichiometric requirement \n c) Stable reaction

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One of the reactant is usually present in excess in order to maintain reasonably fast over-all reaction rates and to satisfy the stoichiometric requirements of the nitration reaction.

What does D.V.S stand for?

Dehydrating value of sulphuric acid

What do we denote Nitric ratio as?

Nitric ratio is denoted by ‘R’ and it is the ratio of the weights of 100 per cent HN03 to weight of material being nitrated

What do you mean by Nitric ratio?

Ratio of wt of 100% HNO3 / wt of materials being nitrated

What is NO2+ called?

NITRYL/NITRONIUM ION.

To calculate D.V.S. from the mixed-acid analysis the formula is, D.V.S

S / (EN / R+W)

Where:

S = percent actual H2SO4, \n N = per cent actual HNO3 \n W = per cent water \n E = water equivalent of material to be nitrated and \n R = nitric ratio.

Which of the following is the correct formula for nitric acid?

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a) R= N/X \n b) EN/R = EX \n c) X= N/R

ALL. The formula for nitric acid (R) is R= N/X which can be rearranged to get the other formulae.

What happens while decreasing the D.V.S value?

It is found experimentally that increasing D.V.S. favours high stability of the nitrator charge, while decreasing the D.V.S results in lowering stability.

Why is keeping the D.V.S ratio high, a stability factor?

Tends to complete nitration and esterification reaction

Complete the reaction? C6H6 + NO2-OH ——–> _______ + H2O. (NITRATION OF BENZENE)

C6H6 + NO2-OH ——–> __**C6H5-NO2**__ + H2O. C

The losses incidental to the neutralization of the ==**nitrobenzene**== are directly proportional to what?

a) Number of washes given \n b) The amount of water used

What percent of nitric acid is added to the nitrator to produce a mixed acid during the process of continuous nitration with @@**fortified**@@ spent acid?

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@@means nutrients that arent normally there are present@@

During vigourous agitation in continous nitration for the production of nitrobenzene, sufficient **63 percent nitric acid** is added to the nitrator to produce a mixed acid containing 4 per cent HNO3.

What is the formula of m-Dinitro benzene?

(1,3)-Dinitrobenzene

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‘m’ stands for ‘meta’, and it’s position is 3rd Carbon on the benzene ring, whereas 2 and 4 are ortho and para respectively.

For preparation of Chloro-nitrobenzene which of the following position gives highest amount?

For the production of Chloro-nitrobenzene we get 66.9% at **ortho position** and 33.1% at para position.

Complete the above reaction: C6H5CH3 + 18H2SO4 + 18HNO3 ——–> ____ HNOSO4 + 7CO2 + 22H2O

C6H5CH3 + 18H2SO4 + 18HNO3 —–> **18HNOSO4** + 7CO2 + 22H2O.

What is used for the production if dyes and isocyanates?

The **nitrotoluenes** are used primarily as intermediates in the dye industry and the toluene diamines derived from dinitrotoluenes are used as intermediates for the production of isocyanates.

When naphthalene is nitrated under optimal conditions, what product do we get?

a(alpha)-nitrotoluene

The purification of products, during the formation of a(alpha)-nitronaphthalene , depends upon the following

a) Use of minimum solvent \n b) Constant agitation

In which column the crude nitroparaffins and water are stripped out of the solvent, during the “preparation of Nitroparaffins”?

Stripping column

During the process of nitration of propane, the main production of nitroparaffins include what ?

By the process of nitration of propane, the main production of nitroparaffins includes nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane. The nitration is done in the vapor phase.