(ΔH – ΔU) for the formation of carbon monoxide (CO) from its elements at 298 K is (R = 8.314 JK–1 mol–1)
Which of the following is fully fluorinated polymer?
The decreasing order of nucleophilicity among the nucleophiles is
Due to the presence of an unpaired electron, free radicals are
Which of the following is the correct order of decreasing SN2 reactivity? (X is a halogen)
For which of the following parameters the structural isomers C2H5OH and CH3OCH3 would be expected to have the same values? (Assume ideal behavior)
The coordination number and the oxidation state of the element E in the complex [E(en)2(C2O4)]NO2 (where (en) is ethylene diamine) are, respectively
Which of the following facts about the complex [Cr(NH3)6]Cl3 is wrong?
The coordination number of a central metal atom in a complex is determined by
The value of the ‘spin only’ magnetic moment for one of the following configurations is 2.84 BM. The correct one is
The type of isomerism present in nitropentamine chromium (III) chloride is
In the coordination compound, K4[Ni(CN)4], the oxidation state of nickel is
Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being
The lanthanide contraction is responsible for the fact that
A reduction in atomic size with increase in atomic number is a characteristic of elements of
The number of d electrons retained in Fe2+ (At. no. Fe = 26) ions is
A metal M readily forms its sulphate MSO4 which is water-soluble. It forms its oxide MO which becomes inert on heating. It forms an insoluble hydroxide M(OH)2 which is soluble in NaOH solution. Then M is
During the process of electrolytic refining of copper, some metals present as impurity settle as 'anode mud'. These are
Which one of the following orders presents the correct sequence of the increasing basic nature of the given oxides?
According to the periodic law of elements, the variation in properties of elements is related to their
The set representing the correct order of ionic radius is
Which one of the following characteristics is not correct for physical adsorption?
3 g of activated charcoal was added to 50 mL of acetic acid solution (0.06 N) in a flask. After an hour it was filtered and the strength of the filtrate was found to be 0.042 N. The amount of acetic acid adsorbed (per gram of charcoal) is:
Which of the following statement is incorrect regarding physissorptions?
In Langmuir’s mode of adsorption of a gas on a solid surface
The disperse phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged, respectively. Which of the following statements is NOT correct?
In conversion of limestone to lime,
CaCO3(s) → CaO(s) + CO2(g)
The values of ΔH° and ΔS° are +179.1 kJ/mol and 160.2 J/K respectively at 298 K and 1 bar. Assuming that ΔH° and ΔS° do not change with temperature, temperature above which conversion of limestone to lime will be spontaneous is
Standard entropy of X2, Y2 and XY3 are 60, 40 and 50 J K–1 mol–1, respectively. For the reaction, 1/2 X2 + 3/2 Y2 → XY3, ΔH = –30 kJ, to be at equilibrium, the temperature will be
The heat required to raise the temperature of 1 mole substance by 1°C is called
For a first order reaction, (A) → products, the concentration of A changes from 0.1 M to 0.025 M in 40 minutes. The rate of reaction when the concentration of A is 0.01 M is
For the non-stoichiometric reaction 2A + B → C + D, the following kinetic data were obtained in three separate experiments, all at 298 K.
The rate law for the formation of C is
A reaction involving two different reactants can never be
The rate of a chemical reaction doubles for every 10ºC rise of temperature. If the temperature is raised by 50ºC, the rate of the reaction increases by about
The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr.
NO(g) + Br2(g) ↔ NOBr2(g)
NOBr2(g) + NO(g) → 2NOBr(g)
If the second step is the rate determining step, the order of the reaction with respect to NO(g) is
A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of carbon monoxide is doubled, with everything else kept the same, the rate of reaction will be
The half life of a radioactive isotope is three hours. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 hours would be
Conductivity (unit Siemen’s S) is directly proportional to area of the vessel and the concentration of the solution in it and is inversely proportional to the length of the vessel then the unit of the constant of proportionality is
In a hydrogen-oxygen fuel cell, combustion of hydrogen occurs to
Freezing point of an aqueous solution is (-0.186)°C. Elevation of boiling point of the same solution is Kb = 0.512 °C, Kf = 1.86 °C, find the increase in boiling point.
The solubility product of a salt having general formula MX2, in water is 4 × 10–12. The concentration of M2+ ions in the aqueous solution of the salt is
The correct relationship between free energy change in a reaction and the corresponding equilibrium constant Kc is
Among the following acids which has the lowest pKa value?
Solubility product of silver bromide is 5.0x10-13. The quantity of potassium bromide (molar mass taken as 120 g mol–1) to be added to 1 litre of 0.05 M solution of silver nitrate to start the precipitation of AgBr is
A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of 290 mm at 300 K. The vapour pressure of propyl alcohol is 200 nm. If the mole fraction of ethyl alcohol is 0.6, its vapour pressure (in mm) at the same temperature will be
If α is the degree of dissociation of Na2SO4, the vant Hoff’s factor (i) used for calculating the molecular mass is