List of practice Questions

The value of magnetic field at point \( O \) in the given figure is:
value of magnetic field at point O
A piece of a diamagnetic material, free to move when placed in a uniform magnetic field:
An AC source is connected to a resistor and an inductor in series. The voltage across the resistor and inductor are 8 V and 6 V respectively. The voltage of the source is:
A vertically held bar magnet is dropped along the axis of a copper ring having a cut as shown in the diagram. The acceleration of the falling magnet is:
vertically held bar magnet is dropped along the axis of a copper ring
The figure shows the voltage (V) versus the current (I) graphs for a wire at two temperatures \( T_1 \) and \( T_2 \). One can conclude that:
voltage (V) versus the current (I) graphs
If \( R_s \) and \( R_p \) are the equivalent resistances of \( n \) resistors, each of value \( R \), in series and parallel combinations respectively, then the value of \( (R_s - R_p) \) is:
Out of Fe$^{3+}$, Sc$^{3+}$, Cr$^{3+}$ and Co$^{3+}$ ions, the one which is colourless in aqueous solution is:

What amount of electric charge is required for the reduction of 1 mole of MnO$_4^{2-}$ into Mn$^{2+}$?

Out of the following complex compounds, which of the compound will be having the minimum conductance in solution?

Complete the following reactions by writing the structure of the main products:

Student to attempt either option-(A) or (B):
(A) Write the features a molecule should have to act as a genetic material. In the light of the above features, evaluate and justify the suitability of the molecule that is preferred as an ideal genetic material. 
OR 
(B) Differentiate between the following:

  • [(i)] Polygenic Inheritance and Pleiotropy
  • [(ii)] Dominance, Codominance and Incomplete dominance
(ii) Account for the following:
(I) We cannot determine the order of a reaction by taking into consideration the balanced chemical equation.
(II) A bimolecular reaction may become kinetically first order under a specified condition.
Complete each synthesis by giving missing starting material, reagent, or products: (I) \(\text{CH}_3\text{CH}_3 + \text{KMnO}_4, \text{KOH} \longrightarrow \text{?}\)

According to the generally accepted definition of the ideal solution there are equal interaction forces acting between molecules belonging to the same or different species. (This is equivalent to the statement that the activity of the components equals the concentration.) Strictly speaking, this concept is valid in ecological systems (isotopic mixtures of an element, hydrocarbons mixtures, etc.). It is still usual to talk about ideal solutions as limiting cases in reality since very dilute solutions behave ideally with respect to the solvent. This law is further supported by the fact that Raoult’s law empirically found for describing the behaviour of the solvent in dilute solutions can be deduced thermodynamically via the assumption of ideal behaviour of the solvent.
Answer the following questions:
(a) Give one example of miscible liquid pair which shows negative deviation from Raoult’s law. What is the reason for such deviation?
(b) (i) State Raoult’s law for a solution containing volatile components. 
OR 
(ii) Raoult’s law is a special case of Henry’s law. Comment. 
(c) Write two characteristics of an ideal solution.

(i) The initial concentration of N\(_2\)O\(_5\) in the first-order reaction:
\[ \text{N}_2\text{O}_5 (\text{g}) \rightarrow 2 \text{NO}_2 (\text{g}) + \frac{1}{2} \text{O}_2 (\text{g}) \] was \( 1.2 \times 10^{-2} \) mol L\(^{-1}\). The concentration of N\(_2\)O\(_5\) after 60 minutes was \( 0.2 \times 10^{-2} \) mol L\(^{-1}\). Calculate the rate constant of the reaction at 318 K.
\([ \log 6 = 0.778 ]\)
(ii) Carry out the following conversions: (I) Benzaldehyde to Benzophenone
Ribose and 2-deoxyribose have an important role in biology. Among the most important derivatives are those with phosphate groups attached at the 5 position. Mono-, di- and tri-phosphate forms are important, as well as 3-5 cyclic monophosphates. Purines and pyrimidines form an important class of compounds with ribose and deoxyribose. When these purine and pyrimidine derivatives are coupled to a ribose sugar, they are called nucleosides.
Answer the following questions :
(a) What products would be formed when DNA is hydrolyzed? How is DNA different from RNA with reference to structure?
Give reasons:
(I) \([ \text{Ni(CO)}_4 ]\) is diamagnetic whereas \([ \text{NiCl}_4 ]^{2-}\) is paramagnetic. [Atomic number: Ni = 28]
(II) CO is a stronger complexing agent than NH\(_3\).
(III) The trans isomer of complex \([ \text{Co(en)}_2\text{Cl}_2 ]^{+}\) is optically inactive.
Calculate the cell voltage of the voltaic cell which is set up by joining following half-cells at 25°C:
Al/Al$^{3+}$(0.001 M) and Ni/Ni$^{2+}$(0.1 M)
Given: $E^\circ_{\text{Al}} = -1.66$ V, $E^\circ_{\text{Ni}} = -0.25$ V, $n_{\text{Al}} = 3$, $n_{\text{Ni}} = 2$
Complete the following reactions by writing the structural formulae of ‘A’ and ‘B’:
(i) CH$_3$CH=CH$_2$ + HBr $\xrightarrow{\text{Peroxide}}$ ‘A’ $\xrightarrow{KOH}$ ‘B’
(ii) CH$_3$CH$_2$CHCl + alc. KOH $\xrightarrow{\Delta}$ ‘A’ $\xrightarrow{\text{H}_2\text{O}}$ ‘B’ (Main product)
Arrange the following compounds as asked:
(a) In decreasing order of pKb, values: C$_6$H$_5$NH$_2$, (C$_2$H$_5$)$_2$NH, C$_6$H$_5$NHCH$_2$CH$_3$, C$_6$H$_5$NH$_3$
(b) Increasing order of boiling point: C$_6$H$_5$OH, C$_2$H$_5$NH$_2$, (C$_2$H$_5$)$_2$NH, C$_6$H$_5$NH$_2$
(c) Increasing order of solubility in water: C$_6$H$_5$NH$_2$, (C$_2$H$_5$)$_2$NH, C$_6$H$_5$NHCH$_2$CH$_3$
Can sodium ethoxide and t-butyl chloride be used for the preparation of t-butyl ethyl ether? Give suitable explanation. Justify your answer by suggesting the appropriate starting material required for preparation of t-butyl ethyl ether.
Account for the following: (i) Allyl chloride is hydrolyzed more readily than n-propyl chloride.
(ii) Isocyanides are formed when alkyl halides are treated with silver cyanide.
(iii) Methyl chloride reacts faster with OH$^-$ ion in $S_N2$ reaction than t-butyl chloride.
An aromatic compound A$^1$ with molecular formula C$_8$H$_8$O gives positive 2,4-DNP test. It gives yellow precipitate of compound ‘B’ on treatment with sodium hypobromite. Compound ‘A’ does not react with Tollen’s or Fehling’s reagent; on drastic oxidation with KMnO$_4$, it forms a carboxylic acid ‘C’. Elucidate the structures of A, B and C. Also give their IUPAC names.
Give the IUPAC name of above mentioned ether.