Calculate the standard Gibbs free-energy change, ΔG°, and predict the spontaneity of the following reaction at 298 K:
2A(g) + B(g) → 2D(g)
Given:
ΔU° = −10 kJ mol⁻¹
ΔS° = −44 J K⁻¹ mol⁻¹
R = 8.31 J mol⁻¹ K⁻¹
1. −0.6357 kJ mol⁻¹; spontaneous
2. +0.6357 kJ mol⁻¹; non-spontaneous
3. - 1.635 kJ mol⁻¹; spontaneous
4. +1.635 kJ mol⁻¹; non-spontaneous
Subtopic: Spontaneity & Entropy |
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Level 2: 60%+
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Given below is an expression for the rate constant of a first order reaction occurring at a certain temperature, T(K).
\(\ln k = 14\cdot34 - \dfrac{1\cdot25 \times 10^4}{T}~\)
The energy of activation in kcal mol-1 for the reaction is :
(Given : k in \(s^{-1}, R = 1.987 ~\text{cal mol}^{-1} K^{-1})\)
1. 12.42
2. 18.63
3. 14.34
4. 24.84
\(\ln k = 14\cdot34 - \dfrac{1\cdot25 \times 10^4}{T}~\)
The energy of activation in kcal mol-1 for the reaction is :
(Given : k in \(s^{-1}, R = 1.987 ~\text{cal mol}^{-1} K^{-1})\)
1. 12.42
2. 18.63
3. 14.34
4. 24.84
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Select the reagents that reduce nitriles to primary amines:
Choose the correct answer from the options given below:
1. A, B and C only
2. A, D and E only
3. A, C and D only
4. B, D and E only
| A. | (i) LiAlH4; (ii) H2O |
| B. | Sn + HCl |
| C. | H2/Ni |
| D. | Na(Hg)/C2H5OH |
| E. | Br2/aq. NaOH |
Choose the correct answer from the options given below:
1. A, B and C only
2. A, D and E only
3. A, C and D only
4. B, D and E only
Level 4: Below 35%
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The correct statement with regard to the secondary structure of DNA/RNA is :
| 1. | DNA possesses a double strand helix structure and contains thymine as one of the four bases. |
| 2. | DNA possesses a single strand helix structure and contains uracil as one of the four bases. |
| 3. | RNA possesses a double strand helix structure and contains uracil as one of the four bases. |
| 4. | RNA possesses a single strand helix structure and contains thymine as one of the four bases. |
Level 4: Below 35%
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During Lassaigne's test, the elements present in an organic compound are converted from:
| 1. | ionic form to ionic form. |
| 2. | covalent form to ionic form. |
| 3. | ionic form to covalent form. |
| 4. | covalent form to covalent form. |
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Mixture of chloroform and acetone forms a solution with negative deviation from Raoult's law due to :
| 1. | stronger intermolecular forces between chloroform molecules than those between chloroform and acetone molecules. |
| 2. | formation of hydrogen bonding between acetone and chloroform. |
| 3. | repulsive forces. |
| 4. | increase in escaping tendency of molecules of each component. |
Level 4: Below 35%
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In a test tube containing a salt, a few drops of dilute H₂SO₄ was added, which gave colourless vapours having the smell of vinegar. The vapours turned the blue litmus paper red.
Identify the correct anion from the following:
1. Carbonate, \(\mathrm{CO}_3^{2-}\)
2. Sulphide, \(S^{2-}\)
3. Acetate, \(CH_3COO^-\)
4. Sulphate, \(\mathrm{SO}_4^{2-}\)
Identify the correct anion from the following:
1. Carbonate, \(\mathrm{CO}_3^{2-}\)
2. Sulphide, \(S^{2-}\)
3. Acetate, \(CH_3COO^-\)
4. Sulphate, \(\mathrm{SO}_4^{2-}\)
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Identify the correct statement about ClF3 from the following options :
| 1. | It has T-shaped geometry with three lone pairs on Cl atom. |
| 2. | It has T-shaped geometry with two lone pairs on Cl atom. |
| 3. | It has a trigonial pyramidal geometry with two lone pairs on Cl atom. |
| 4. | It has a planar trigonal geometry with two lone pairs on Cl atom. |
Level 4: Below 35%
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Match List I with List II:
Choose the correct answer from the options given below:
1. A-I, B-III, C-II, D-IV
2. A-II, B-IV, C-III, D-I
3. A-III, B-I, C-IV, D-II
4. A-III, B-I, C-II, D-IV
| List-I (Complex) | List-II (Types of isomerism) | ||
| A. | \([{Pr(NH_3)_2Cl_2}]\) | I. | Optical |
| B. | \([Co(en)_3]^{3+}\) | II. | Solvate |
| C. | \([Co(NH_3)_5NO_2]Cl_2\) | III. | Geometrical |
| D. | \([Cr(H_2O)_6]Cl_3\) | IV. | Linkage |
Choose the correct answer from the options given below:
1. A-I, B-III, C-II, D-IV
2. A-II, B-IV, C-III, D-I
3. A-III, B-I, C-IV, D-II
4. A-III, B-I, C-II, D-IV
Level 4: Below 35%
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The number of chlorine atoms present in the organic products X and Y of the following reactions, respectively, are
1. 3 and 3
2. 6 and 6
3. 6 and 3
4. 3 and 6
1. 3 and 3
2. 6 and 6
3. 6 and 3
4. 3 and 6
Subtopic: Aromatic Hydrocarbons - Benzene - Structure, Preparation & Chemical Reactions |
62%
Level 2: 60%+
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