What’s wrong with the following IUPAC name? Tetraaminecopper(II) ion.

What’s wrong with the following IUPAC name?

Cu(NH3)42 +

Tetraaminecopper(II) ion

Correct IUPAC name

Tetraamminecopper(II) ion

ammine, not amine

Cu(NH3)42 +


2-Methylpentan-2,4-diol

C C C C CH

CH3

OH OH

H H

H

H

H

H

H

H

Correct IUPAC name

2-Methylpentane-2,4-diol

C C C C CH

CH3

OH OH

H H

H

H

H

H

H

H


3,7-dimethyloct-6-eneal

C C

CH2CH2CHCH2CHO

CH3

CH3

CH3 H

Correct IUPAC name

3,7-dimethyloct-6-enal

C C

CH2CH2CHCH2CHO

CH3

CH3

CH3 H


Br

Br

Dibromocyclohexane

Correct IUPAC name

trans-1,2-dibromocyclohexane

Br

Br

What’s wrong with the following structure?

Cl O-

Correct structure

Cl O-

Correct structure

Cl O-

Cl O

H

+ H+


C N-

Correct structure

C N-

Correct structure

C N-

H C N

+ H+


C O

Correct structure

C O


N

O O

Correct structure

N

O O


N

O O-

Correct structure

N

O O-


N

O O

+

Nitronium ion

Correct structure

NO O+

Nitronium ion


O

O O

Correct structure

O

O O

What’s wrong with the following representation?

n =

n =

n = n =

2

3

45

n = 1

Energy level diagram


n =

n =

n = n =

2

3

45

2

wrong

n = 1energy gap between n = & n = 2 1

should be greater than that between n = infinity & n =

Correct representation

n =n = n =

3

45

2

n = 1

energy gap between n = & n = 2 1

should be greater than that between n = infinity & n =

n = 2


potentialenergy

reaction coordinate

transition state


potentialenergy

reaction coordinate

transition state

intermediate


Al

Cl

Cl

Al

Cl

Cl Cl

Cl


C C

Cl Cl

H H


Cl Cl

C C

H H


N

H

H

H

B

F

F

F


N B

H

HH

FF

F


Be

Cl

Cl

Be

Cl

Cl

Cl

ClBe


Be

Cl

Cl

Be

Cl

Cl

Cl

Cl

Be


+ OO3 O2UV


O+O3 O2UV


O


[Co(H2O)6]2+ Cl2

-


[Co(H2O)6]2+ 2Cl-


Pt(s) /H2(g) /2H+(aq) Cu2+(aq) /Cu(s)

E o = +0.34V

Cell diagram of the standard electrode potential of Cu2+(aq)/Cu(s) couple


Pt(s) /H2(g, 1atm) /2H+(aq, 1M) Cu2+(aq, 1M) /Cu(s)

E o = +0.34V

Cell diagram of the standard electrode potential of Cu2+(aq)/Cu(s) couple


Cl CF2Cl


Cl CF2Cl

“Fish-hook arrow/ half arrow“ to represent flow of an odd electron.


C+

CH3

H C2H5

HO-

C

CH3

HO H

C2H5


C+

CH3

H C2H5

HO-

C

CH3

HO H

C2H5

Curly arrows flows from –ve charge center to +ve charge center.


CH3 C

O

O-

CH3 C

O

O-


CH3 C

O

O-

CH3 C

O

O-

“” to represent resonance


CH3 F

Negative inductive effect of F


Negative inductive effect of F

CH3 F

“ ” to represent inductive effect


1s2 2s2 2p6 3s2 3p6 4s2 3d2


Electronic configuration should be in ascending order of principal quantum no

1s2 2s2 2p6 3s2 3p6 3d2 4s2


Enthalpy change of combustion of nitrogen = 40 kJ mol-1


+ve/-ve sign should be included in the H values of endothermic/exothermic en

thalpy changes

Enthalpy change of combustion of nitrogen = +40 kJ mol-1


Enthalpy Change of formation of water:

H2 + O2 H2O H = -420 kJ mol-1


Physical states should be included in thermochemical equations.

Enthalpy Change of formation of water:

H2 (g)+ ½O2 (g) H2O(l) H = -420 kJ mol-1

Equations should be balanced.


Partial pressure of H2 – [H2(g)]


[ ] – concentration expressed in terms of mol dm-3

Partial pressure of H2 – PH2(g)

What’s wrong with the following equation?

RCH2OH KCN

RCH2CN

Correct reaction pathway

RCH2OH

RCH2Cl

RCH2CN

PCl5NaCN

alcohol, reflux


CH3 C

O

OH

NaBH4

CH3CH2OH


CH3 C

O

OH

CH3CH2OH1. LiAlH4, ether

2. water


C C

R

H

H

H

LiAlH4RCH2CH3


C C

R

H

H

H

RCH2CH3

H2, Pt


CH3

C C

H

H

H

conc H2SO4

H

H2O

CH3

C C

OSO3H H

H

H

CH3

C C

H

H

HH

OH

oC0 - 10

CH3

C C

H

H

H

conc H2SO4

H

H2O

CH3

C C

OSO3H H

H

H

CH3

C C

H

H

HH

OH



R + NH3C

O

OH

C

O

R

NH2


heat+ NH3 C

O

R

O-NH4

+

R C

O

OH

R C

O

NH2


+NH3

C

O

RR C

O

OH

R C

O

NH2Cl

PCl5

HCl+


CH3 CH2 C

O

OCH3

conc. H2SO4CH3CH2COOH + CH3OH


R C

O

+ CN- R C OH

CN

H

H


R

C

H

O

HCNC

RH

OH

CN

+ C

HO

NCR

H


+

CH3

C

O

OH

I2, NaOHCHI3HCOO-


+

CH3

C

O

I2, NaOHCHI3

HCOO-

H


CH3CONH2

H3O+

CH3COOH + NH3


CH3CONH2

H3O+

CH3COOH + NH4+


RCH2CH2Clconc. H2SO4

RCH=CH2


RCH2CH2Cl RCH=CH2

alcoholic KOH

heat


NH2 NH2

Br2(aq)

Br

Correct reaction pathwayNH2

Br2(aq)Br

NH2

Br

Br

NH2

CH3COCl Br2(aq)

O

NHCCH3

O

NHCCH3

Br

NaOH(aq)

NH2

Br


+ CH3COOHconc. H2SO4

O

C

OCH3

OH


+

O-

CH3COCl

O

C

OCH3


CH3CH CHCH2CH3

O31.

2. H2OCH3CHO + CH3CH2CHO


CH3CH CHCH2CH3

O31.CH3CHO + CH3CH2CHO

2. H2O, Zn


COH

+ NH2NH2

CH NNH2

Correct products

COH

+ NH2NH2

CH NNH2

C

H

N

N C

H


OH

+

N N

OH

N N+

Correct product

+N+

OH

NOH

NN


OH

+ Na2CO3

ONa

2 2 + H2O + CO2

Correct products

OH

+ Na2CO3

ONa

+ NaHCO3

Phenol is less acidic than H2CO3,

but more acidic than HCO3-.


Two dipeptides can be formed from 2-aminoethanoic acid and 2-aminopropanoic acid

+

H

NH2 C

H

COOH

H

NH2 C

H

C

O

N

HH

NH2 C COOH

CH3

H

C COOH

CH3

+

NH2 C

H

CH3

C

O

N

H

H

C COOH

NH2 C

H

COOH

CH3

H

NH2 C COOH

H

H

Correct products

C

H

HOOC

N

H

C

O

C

H

H

NH2

CH3 *H

C

H

CN

H

C

NH2

COOH

H

O

* CH3

C

H

H

COOHN

C

H

O

C

H

CH3

NH2

* C

HC

H

HCH3 * CN

NH2

O

H

COOH


CH3 CH2 C CH2 CH2 CH3

H

OH

conc. H2SO4

heat

CH3CH2

C C

H H

CH2CH3

Correct products


H

OH

CH3CH2

C C

H H

CH2CH3

CH3CH2

C C

H

H

CH2CH3

C C

H H

CH3CH2CH2CH3

C C

H

HCH3

CH2CH2CH3

conc. H2SO4

heat


heatCH3 CH2 C CH2 CH2 CH3

CH3CH2

C C

H H

CH2CH3

CH3

Br

alcoholic KOH

Correct products

CH3CH2

C C

H H

CH2CH3

CH3CH2

C C

H

H

CH2CH3

C C

H H

CH3CH2CH2CH3

C C

H

HCH3

CH2CH2CH3

alcoholic KOH

heat

CH3

Br

C C

CH2CH2CH3

H

H

CH2CH3


Correct products

C C

X

H C

C

H

H

B-

C C

X

H C

C

H

H

B-

C C

X

H C

C

H

HB

-


Na + O2(g)(s)4 2Na2O (s)

Correct product

Na + O2(g)(s)4 2Na2O (s)

Na2O2+Na(s)2 O2(g) (s)

main reaction

side reaction

What’s wrong with the following reaction conditions?

using AgNO3(aq) to detect chloride ion

Correct reaction conditions

using AgNO3(aq) + HNO3(aq)

to detect chloride ion


using glowing splint to detect hydrogen;


using burning splint in the test of hydrogen


using BaCl2(aq) to detect sulphate ion


using BaCl2(aq) + HCl(aq)

to detect sulphate ion


using LiAlH4, water in the reduction of

carbonyl compounds


using LiAlH4, ether in the

reduction of carbonyl compounds

LiAlH4 + 4H2O Li+ + Al3+ + 4OH- + 4H2


using NaNO3(s) + HCl(aq)

in the azotization of aromatic amines


using NaNO2(s) + HCl(aq) (<5oC)

in the azotization of aromatic amines

What’s wrong with the following description?

in Lucas Test (to distinguish 1o, 2o & 3o alcohol), 3o alcohol forms precipitate readily as alkyl halide is immiscible

with water

Correct description

in Lucas Test (to distinguish 1o, 2o & 3o alcohol), 3o alcohol turns turbid readily as alkyl halide is immiscible with water.


Landfilling is an appropriate disposal method for PVC.

Correct description

Landfilling is not regarded as an appropriate disposal method for PVC because PVC is non-biodegradable;

The proper way is by incineration (with adequate supply of air at sufficient higher temperature) and treat the flue gas in wet scrubber with Na2CO3(aq).


first emission line in the Balmer series involves electronic transition between n = 2 to n = 0.

Correct description

quantum number can have values 1,2,3 etc; first emission line in Balmer series involves electronic transition between n = 3 to 2; convergence limit in Balmer series involves electronic transition between n = infinity to 2.

What’s wrong with the following expression?

Kc =[CH3COOH(aq)]

CH3COOH(aq) + H2O(l) CH3COO-(aq) + H3O

+(aq)

[CH3COO-(aq)] [H3O+(aq)]

Correct expression

OR

CH3COOH(aq) + H2O(l) CH3COO-(aq) + H3O

+(aq)

Kc =

Ka =[CH3COOH(aq)]

[CH3COOH(aq)] [H2O(l)]




Kc = [CH3COOC2H5(l)]

+ H2O(l)+C2H5OH(l)CH3COOH CH3COOC2H5(l)

[CH3COOH(l)][C2H5OH(l)]

Correct expression

Kc = [CH3COOC2H5(l)] [H2O(l)]

+ H2O(l)+C2H5OH(l)CH3COOH CH3COOC2H5(l)

[CH3COOH(l)][C2H5OH(l)]


AgCl(s) Ag+(aq) + Cl

-(aq)

Kc = [Ag

+(aq)][Cl

-(aq)]

[AgCl(s)]

Correct expression

Cl-(aq)AgCl(s) Ag

+(aq) +

[Ag+(aq)][Cl

-(aq)]Kc' =

[AgCl(s)] is a constant term.


The decay of carbon-14 starts after the death of living things.

Correct expression

The ratio of carbon-12 and carbon-14 remains unchanged in a living organism, but decreases slowly after the death of living things.


In paper chromatography, cellulose in the filter paper is the stationery phase.

Correct expression

In paper chromatography, the thin film of water on the chromatography paper acts as the stationary phase and that partition is the underlying principle of paper chromatography.


criteria in choosing an indicator – pH range of colour change close to the equivalence point

Correct expression

criteria in choosing an indicator – the pH range of colour change of the indicator falls into the steepest part of the titration curve/ pKi is very close to the pH of the solution at equivalence point.


A rise in temp increases the forward reaction rate and the equilibrium position shifts to the product side.

Correct expression

A rise in temp. increases both the forward & backward reaction rates. For endothermic reaction the extent of increase in forward reaction rate is greater than that of backward reaction rate. Thus the position of equilibrium shifts to the product side. In case of endothermic/exothermic reaction, Kc increases/decreases with temp.


catalyst increases both reaction rate & yield.

catalyst lowers the activation energy of the reaction.

Correct expression

catalyst increases the reaction rate but yield remains unchanged.

catalyst provides a new pathway with lower activation energy.


b.p. of H2O > OF2 because intermolecular

hydrogen bond exists in water.

Correct expression

b.p. of H2O > OF2 because intermolecular hydr

ogen bond exists in water and van der Waals’ force between OF2.

more energy is needed to overcome hydrogen bond, accounting for the higher boiling point.


Boiling point of H2O > H2S because O is more

electronegative and forms stronger hydrogen bonding.

Correct expression

Boiling point of H2O > H2S

because O is more electronegative

intermolecular hydrogen bond in H2O

Van der Waals’ forces in H2S is weaker

more energy is needed to overcome hydrogen bond, accounting for the higher boiling point.


hcp, fcc and bcc are close-packing arrangement.

Correct expression

Hexagonal close-packing and face-centred cubic close-packing have the maximum co-ordination number, which is equal to 12. Body-centred cubic has open structure and the coordination number is equal to 8.


NaCl has ‘face-centred cubic structure’ and CsCl has ‘body-centred cubic structure’

Correct expression

In NaCl, both Na+ and Cl- ions adopt face-centred cubic lattices, which interpenetrate each other. The structure shows 6:6 coordination.

In CsCl, both Cs+ and Cl- ions adopt simple cubic lattices, which interpenetrate each other. The structure shows 8:8 coordination.


oxidative rancidity of oils and fats involve RCOO.

Correct expression

oxidative rancidity of oils and fats involve alkylperoxyl radical (ROO.) but not the carboxyl radical (RCOO.);


The functional group in benzoic acid is ‘alkanoic acid’ and ‘alkanol’ is the functional group of phenol.

Correct expression

‘Carboxylic acid’ is the functional group of benzoic acid. ‘Hydroxyl group’ is the functional group of phenol.


“Chromium is harmful”

Correct expression

Chromium compounds are toxic to aquatic life.


Aspirin has sude effects.

Correct expression

Aspirin could cause damage to stomach lining.


Order is the sum of the powers of the concentration terms in the rate equation.

Correct expression

Order is the sum of the powers of the concentration terms in the experimentally determined rate equation.


Half-life of a first order reaction increases with initial concentration.

Correct expression

Half-life of a first order reaction is independent of initial concentration or pressure.


With an alkali, halogen forms halide and halate(V).

Correct expression

With an alkali, chlorine forms ClO- and ClO3-

under different conditions, bromine forms mainly BrO3

- with some BrO-, and iodine only IO3-.


Boric acid is a tribasic acid.

Correct expression

Boric acid is a monobasic acid.


CCl4 is stable towards water, but SiCl4 hydrolyses readily in water. This is because C is more electronegative than Si.

Correct expression

Low-lying vacant orbital is not available in carbon.


Phenol is more acidic than ethanol because the negative charge on the phenoxide ion can delocalise into the benzene ring.

Correct expression

Due to the delocalization of the negative charge, the phenoxide ion is stablized. The following equilibrium shifts to the RHS.

OH O-

+ H+


Tertiary carbocation is more stable than the primary carbocation.

Correct expression

Positive inductive effect of the methyl group stabilises the tertiary carbocation.

Tertiary carbocation is more stable than the primary carbocation.

What’s wrong with the following IUPAC name? Tetraaminecopper(II) ion.

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Transcript of What’s wrong with the following IUPAC name? Tetraaminecopper(II) ion.