($$\Delta H-\Delta U$$) for the formation of carbon monoxide (CO) from its elements at 298 K is : (R = 8.314 J K–1 mol–1)

The standard enthalpy of formation $${\Delta }_f{H}^o$$ at 298 K for methane, CH4(g), is –74.8 kJ mol–1. The additional information required to determine the average energy for C – H bond formation would be :

The enthalpy changes for the following processes are listed below : Cl2(g) = 2Cl(g), 242.3 kJ mol–1 I2(g) = 2I(g), 151.0 kJ mol–1 ICl(g) = I(g) + Cl(g), 211.3 kJ mol–1 I2(s) = I2(g), 62.76 kJ mol–1 Given that the standard states for iodine and chlorine are I2(s) and Cl2(g), the standard enthalpy of formation for ICl(g) is :

The increasing order of the rate of HCN addition to compounds A – D is (A) HCHO (B) CH3COCH3 (C) PhCOCH3 (D) PhCOPh

The correct order of increasing acid strength of the compounds

How many moles of magnesium phosphate Mg3(PO4)2 will contain 0.25 mole of oxygen atoms?

Density of a 2.05M solution of acetic acid in water is 1.02 g/mL The molality of the solution is

Among the following mixtures, dipole-dipole as the major interaction, is present in

18 g of glucose (C6H12O6) is added to 178.2 g of water. The vapour pressure of water for this aqueous solution at 100oC is

Phosphorus pentachloride dissociates as follows, in a closed reaction vessel PCl5 (g) $$\leftrightharpoons$$ PCl3 (g) + Cl2 (g) If total pressure at equilibrium of the reaction mixture is P and degree of dissociation of PCl5 is x, the partial pressure of PCl3 will be

The equilibrium constant for the reaction SO3 (g) $$\leftrightharpoons$$ SO2 (g) + 1 \over 2 O2 (g) is Kc = 4.9 $$\times$$ 10–2. The value of Kc for the reaction 2SO2 (g) + O2 (g) $$\leftrightharpoons$$ 2SO3 (g) will be :

Given the data at 25oC, Ag + I- $$\to$$ AgI + e- , Eo = 0.152 V Ag $$\to$$ Ag+ + e-, Eo = -0.800 V What is the value of log Ksp for AgI? (2.303 RT/F = 0.059 V)

Resistance of a conductivity cell filled with a solution of an electrolyte of concentration 0.1 M is 100$$\Omega$$. The conductivity of this solution is 1.29 S m–1. Resistance of the same cell when filled with 0.2 M of the same solution is 520 $$\Omega$$, The molar conductivity of 0.02 M solution of the electrolyte will be

The molar conductivities $${\wedge }_{NaOAc}^o$$ and $${\wedge }_{HCl}^o$$ and at infinite dilution in water at 25oC are 91.0 and 426.2 Scm2/mol respectively. To calculate $${\wedge }_{HOAc}^o$$ , the additional value required is

The “spin-only” magnetic moment [in units of Bohr magneton, (µB)] of Ni2+ in aqueous solution would be : (Atomic number of Ni = 28)

Lanthanoid contraction is caused due to :

A metal, $$M$$ forms chlorides in its $$+2$$ and $$+4$$ oxidation states. Which of the following statements about these chlorides is correct?

The decreasing values of bond angles from NH3 (106o) to SbH3 (91o ) down group-15 of the periodic table is due to

In which of the following molecules/ions are all the bonds not equal?

Which of the following molecules/ions does not contain unpaired electrons?