List of practice Questions

Distilled water boils at 373.15 K and freezes at 273.15 K. A solution of glucose in distilled water boils at 373.202 K. What is the freezing point (in K) of the same solution? (For water, \( K_b = 0.52 \) kg mol\(^{-1}\), \( K_f = 1.86 \) kg mol\(^{-1}\))
Identify the correct statements from the following: A) At 298 K, the potential of the hydrogen electrode placed in a solution of pH = 10 is -0.59 V.
B) The limiting molar conductivity of \( \text{Ca}^{2+} \) and \( \text{Cl}^- \) is 119 and 76 \( \text{S cm}^2 \text{mol}^{-1} \), respectively. The limiting molar conductivity of \( \text{CaCl}_2 \) is 195 \( \text{S cm}^2 \text{mol}^{-1} \).
C) The correct relationship between \( K_c \) and \( E_{\text{cell}} \) is \( E_{\text{cell}} = \frac{2.303RT}{nF} \log K_c \).
For a first-order reaction, a plot of \( \ln k \) (y-axis) and \( \frac{1}{T} \) (x-axis) gave a straight line with a slope equal to \( -10^4 \) and an intercept equal to 2.303 (on the y-axis). What is the activation energy \( E_a \) (in kJ/mol) of the reaction? (Given \( R = 8.314 \, \text{J mol}^{-1} \text{K}^{-1} \))
Identify the element for which \( +1 \) oxidation state is more stable than \( +3 \) oxidation state.
Observe the oxides \( CO, B_2O_3, SiO_2, CO_2, Al_2O_3, PbO_2, Tl_2O_3 \). The number of acidic oxides in the list is:
The common components of photochemical smog are:
The number of activating and deactivating groups of the following are respectively: \[ -OCH_2CH_3, -COCH_3, -NHCOCH_3, -COOCH_3, -SO_3H \]
Consider the following pairs: (A) NO\(_2\) \(>\) O\(_3\) \(>\) H\(_2\)O (Bond angle)
(B) HF \(>\) H\(_2\)O \(>\) NH\(_3\) (Dipole moment)
(C) I\(_2\) \(>\) F\(_2\) \(>\) N\(_2\) (Bond length) Which of the above pairs are correctly matched?
The standard enthalpy of formation (\(\Delta H_f^\circ\)) of ammonia is -46.2 kJ/mol. What is the \(\Delta H_f^\circ\) of the following reaction? \[ N_2(g) + 3H_2(g) \rightarrow 2NH_3(g) \]
Observe the following reactions: \[ \text{I. } H_2O(l) + 2Na(s) \rightarrow 2NaOH(aq) + H_2(g) \] \[ \text{II. } 2H_2O(l) + 2F_2(g) \rightarrow 4H^+(aq) + 4F^-(aq) + O_2(g) \] Identify the correct statement:
What is the correct stability order of \( KO_2, RbO_2, CsO_2 \)?
The heights of the transmitting and receiving antennas are 33.8 m and 64.8 m respectively. The maximum distance between the antennas for satisfactory communication in line of sight mode is:
(Radius of the earth = 6400 km)
Identify the pair of species having the same energy from the following: (The number given in the bracket corresponds to the principal quantum number (n) in which the electron is present.)
Identify the pair of elements in which the number of s-electrons to p-electrons ratio is 2:3:
In a series LCR circuit, if the current leads the source voltage, then:
If the amplitude of the magnetic field part of a harmonic electromagnetic wave in vacuum is \( 270 \) nT, the amplitude of the electric field part of the wave is:
At room temperature, gaseous hydrogen is bombarded with a beam of electrons of 13.6 eV energy. The series to which the emitted spectral line belongs to:
An element consists of a mixture of three isotopes A, B, and C of masses \( m_1 \), \( m_2 \), and \( m_3 \) respectively. If the relative abundances of the three isotopes A, B, and C is in the ratio 2:3:5, the average mass of the element is:
A rectangular coil of 400 turns and \(10^{-2} \, \text{m}^2\) area, carrying a current of 0.5 A is placed in a uniform magnetic field of 1 T such that the plane of the coil makes an angle of 60° with the direction of the magnetic field. The initial moment of force acting on the coil in Nm is:
The most exotic diamagnetic materials are:
Two circular coils of radii \(r_1\) and \(r_2\) (\(r_1 \ll r_2\)) are placed coaxially with their centers coinciding. The mutual inductance of the arrangement is:
The efficiency of a reversible heat engine working between two temperatures is 50\%. The coefficient of performance of a refrigerator working between the same two temperatures but in reverse direction is:
The total internal energy of 4 moles of a diatomic gas at a temperature of \(27^\circ C\) is: (Universal gas constant \( R = 8.31 \, \text{J mol}^{-1} \text{K}^{-1} \))
The energy required to take a body from the surface of the earth to a height equal to the radius of the earth is \( W \). The energy required to take this body from the surface of the earth to a height equal to twice the radius of the earth is:
A steel wire of length 3 m and a copper wire of length 2.2 m are connected end to end. When the combination is stretched by a force, the net elongation is 1.05 mm. If the area of cross-section of each wire is 6 mm², then the load applied is: (Young’s moduli of steel and copper are respectively \(2 \times 10^{11} \, \text{Nm}^{-2}\) and \(1.1 \times 10^{11} \, \text{Nm}^{-2}\)).