Classify the following reactions in one of the reaction type studied in this unit.
(a) CH3CH2Br + HS- → CH3CH2SH + Br-
(b) (CH3)2C = CH2 + HCl → (CH3)2ClC-CH3
(c) CH3CH2Br + HO- → CH2 = CH2 + H2O + Br-
(d) (CH3)3C - CH2OH + HBr → (CH3)2CBrCH2CH3 + H2O
(a) It is an example of substitution reaction as in this reaction the bromine group in bromoethane is replaced by the -SH group.
(b) It is an example of addition reaction as in this reaction two reactant molecules combine to form a single product.
(c) It is an example of elimination reaction as in this reaction hydrogen and bromine are removed from bromoethane to give ethene.
(d) In this reaction, substitution takes place, followed by a rearrangement of atoms and groups of atoms.
What are hybridisation states of each carbon atom in the following compounds ?
(i) CH2=C=O,
(ii) CH3CH=CH2,
(iii) (CH3)2CO,
(iv) CH2=CHCN,
(v) C6H6
Explain the terms Inductive and Electromeric effects. Which electron displacement effect explains the following correct orders of acidity of the carboxylic acids?
(a) Cl3CCOOH > Cl2CHCOOH > ClCH2COOH
(b) CH3CH2COOH > (CH3)2CHCOOH > (CH3)3C.COOH
Write bond line formulas for : Isopropyl alcohol, 2,3-Dimethyl butanal, Heptan-4- one.
Give condensed and bond line structural formulas and identify the functional group(s) present, if any, for :
(a) 2,2,4-Trimethylpentane
(b) 2-Hydroxy-1,2,3-propanetricarboxylic acid
(c) Hexanedial
Indicate the σ and π bonds in the following molecules :
(i) C6H6,
(ii) C6H12,
(iii) CH2Cl2,
(iv) CH2=C=CH2,
(v) CH3NO2,
(vi) HCONHCH3
Identify the reagents shown in bold in the following equations as nucleophiles or electrophiles:
(a) CH3COOH + HO- → CH3COO- + H2O
(b) CH3COCH3 + C-N → (CH3)2 C (CN) (OH)
(c) C6H5 + CH3C+O → C6H5COCH3
For the following bond cleavages, use curved-arrows to show the electron flow and classify each as homolysis or heterolysis. Identify reactive intermediate produced as free radical, carbocation and carbanion.
Which of the following represents the correct IUPAC name for the compounds concerned?
(a) 2,2-Dimethylpentane or 2-Dimethylpentane
(b) 2,4,7-Trimethyloctane or 2,5,7-Trimethyloctane
(c) 2-Chloro-4-methylpentane or 4-Chloro-2-methylpentane
(d) But-3-yn-1-ol or But-4-ol-1-yne
Draw the resonance structures for the following compounds. Show the electron shift using curved-arrow notation.
(a) C6H5OH
(b) C6H5NO2
(c) CH3CH=CHCHO
(d) C6H5–CHO
(e) C6 H5 - C+H2
(f) CH3CH = CHC+H2
Which of the following carbocation is most stable ?
How do you account for the formation of ethane during chlorination of methane?
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
What are the common physical and chemical features of alkali metals?
Calculate the molecular mass of the following:
(i) H2O
(ii) CO2
(iii) CH4
Assign oxidation number to the underlined elements in each of the following species:
(a) NaH2PO4
(b) NaHSO4
(c) H4P2O7
(d) K2MnO4
(e) CaO2
(f) NaBH4
(g) H2S2O7
(h) KAl(SO4)2.12 H2O
What is the basic theme of organisation in the periodic table?
Explain the formation of a chemical bond.
Choose the correct answer. A thermodynamic state function is a quantity
(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only.
A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.
a) What is the initial effect of the change on vapour pressure?
b) How do rates of evaporation and condensation change initially?
c) What happens when equilibrium is restored finally and what will be the final vapour pressure?
Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.
At 0°C, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?
The mass of an electron is 9.1 × 10–31 kg. If its K.E. is 3.0 × 10–25 J, calculate its wavelength.
For the reaction
2 A(g) + B(g) → 2D(g)
ΔU0 = –10.5 kJ and ΔS0 = –44.1 JK–1.
Calculate ΔG0 for the reaction, and predict whether the reaction may occur spontaneously.
Why is benzene extra ordinarily stable though it contains three doublebonds?
What are the common physical and chemical features of alkali metals?
What properties of water make it useful as a solvent? What types of compound can it (i) dissolve, and (ii) hydrolyse?
Would you expect the first ionization enthalpies for two isotopes of the same element to be the same or different? Justify your answer.
When an alkali metal dissolves in liquid ammonia the solution can acquire different colours. Explain the reasons for this type of colour change.
Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% dioxygen by mass.
How would you explain the fact that the first ionization enthalpy of sodium is lower than that of magnesium but its second ionization enthalpy is higher than that of magnesium?