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
Which one of the following aqueous solutions will exhibit highest boiling point?
Two solutions of a substance (non electrolyte) are mixed in the following manner:
480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution
What is the molarity of the final mixture?
Benzene and toluene form nearly ideal solutions. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20°C for a solution containing 78 g of benzene and 46 g of toluene in torr is
How many unit cells are present in a cube-shaped ideal crystal of NaCl of mass 1.00 g? [Atomic masses: Na = 23, Cl = 35.5]
In a compound, atoms of element Y form ccp lattice and those of element X occupy 2/3rd of tetrahedral voids. The formula of the compound will be
If Z is a compressibility factor, van der Waals equation at low pressure can be written as
Equal masses of methane and oxygen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by oxygen is
According to the kinetic theory of gases, in an ideal gas, between two successive collisions a gas molecule travels
In van der Waals equation of state of the gas law, the constant b is a measure of
The bond order in NO is 2.5 while that in NO+ is 3. Which of the following statements is true for these two species?
A square planar complex is formed by hybridisation of which atomic orbitals?
Which of the following sets of quantum numbers is correct for an electron in 4f orbital?
Which of the following statements in relation to the hydrogen atom is correct?
If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will
With increase of temperature, which of these changes?
In the reaction,
2Al (s) + 6HCl (aq) → 2Al3+ (aq) + 6Cl– (aq) + 3H2 (g)
The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SO3Na (Mol. Wt. 206). What would be the maximum uptake of Ca2+ ions by the resin when expressed in mole per gram resin?