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At certain temperature the value of pkw is 13.4 the measured ph of a solution at same temperature is 7. The solution is

Kw = [H+][OH−] = 13.4In neutral water, [H+] = [OH−]If we calculated the pH of H2O from the above value, it come to be 6.7So, the... View Article

The specific rate constant of a first order reaction depends on the (a)concentration of the reactant (b)concentration of the product (c) time (d)temperature

The correct answer is (d) temperature First-order reaction A first-order reaction can be defined as a chemical reaction in which the reaction... View Article

Vapour density of a metal chloride is 66. Its oxide contains 53% metal. The atomic weight of the metal is

Calculation of Equivalent weight of metal:Let the weight of metal oxide to be 100 g.weight of metal = 53 g weight of oxygen = 47 g.Now, as we all... View Article

Non-metals react with oxygen to form _ or __.

Non-metals react with oxygen to form acidic oxides or neutral oxides. C(s) + O2(g) --> CO2(g) Carbon + Oxygen --> Carbon dioxide... View Article

Four monobasic acids a, b, c and d have the values as – 11.5, –7.5, –12.4 and – 8.9 kcal/mol. when they are neutralized by a common base the acidic character or base the order

The enthalpy of neutralization is the change in enthalpy that occurs when one equivalent of an acid and one equivalent of a base undergo a... View Article

if successive ionisation energies of an element are 7.9 ev, 13.2 ev and 247.8 ev respectively, the element is expected to be

The ion must invest a lot of energy (247.8 eV) to release the third electron after releasing two electrons in a row. This indicates that the ion... View Article

a compound with empirical formula xy2, has the vapour density equal to its empirical formula weight, its molecular formula is

The empirical formula for a compound of X and Y is XY2. It has the same vapour density as its empirical formula weight. The molecular weight is... View Article

Each of the following ion contains vanadium in +5 oxidation state except:Each of the following ion contains vanadium in +5 oxidation state except: VO+2, V(OH)+4, VO2+, [VO3OH]2−

VO2+, V(OH)4+, VO2+, [VO3OH]2− Answer In VO2+, the oxidation state of vanadium is +4. In all other complexes, it is +5.... View Article

Basicity increases down the group

As the atomic radius lowers, the ionisation energy decreases, implying that the tendency to lose electrons increases, implying an increase in... View Article

Assertion: All homogenous substances are pure. Reason: Alloys are homogeneous mixtures of solids. A. Both assertion and reason are correct and reason is the correct explanation for assertion. B. Both assertion and reason are correct but reason is not the correct explanation for assertion. C. Assertion is correct but reason is incorrect D. Assertion is incorrect but reason is correct

Alloys are discovered to be homogenous mixes of two or more metals. However, just because an alloy is homogeneous doesn't mean it has to be... View Article

A brown ring is formed in the ring test for (no3)-,i.e. nitrate ion. it is due to the formation of

When freshly prepared solution of FeSO4 is added in a solution containing NO−3 ion, it leads to formation of a brown coloured complex. This is... View Article

Bell metal contains 80% copper. The mass of Bell metal which contains 1.5×10^20 atoms of copper is

6.022 × 1023 atoms = 1 moleThen 1.5 × 1020 = 1 ×1.5 x 1020/6.022 × 1023= 0.00025 moles molar mass of Cu is 64mass = moles... View Article

correct electronic configuration of d-orbital of iron in complex anion [fe(cn)6]4–is(atomic no. of iron is 26)

K4[Fe(CN)6] Since CN– is strong field ligand all the electrons get paired.Fe ground state: [Ar]3d64s2Fe2+:3d64s0... View Article

de broglie wavelength associated with an electron accelerated through a potential difference of 200 v is nearly

Here, V = 100voltwavelength = Planck's Constant/Momentum De-Broglie wavelength, λ = (12.27/√V)Å = 12.27/√100 = 1.227Å In this case the wavelegth... View Article

The entropy change involved in the isothermal reversible expansion of 2 moles of an ideal gas from avolume of 10dm^3 to a volume of 100 dm^3 at 27^0C is

Entropy change for an isothermal process isΔS = 2.303Rlog(V2/V1)ΔS = 2.303×2×8.314×log(100/10)=38.294J/mol/K... View Article

Assertion : Fluorine (F_(2)) is a stronger oxidising agent than chlorine. Reason : Fluorine is more electrongegative than chlorine.

Because fluorine is more electronegative than chlorine, it may more easily and strongly attract a shared pair of electrons.As a result, it... View Article

Assertion: Plaster of paris is stored in a moisture proof container. Reason: Plaster of paris set into a hard mass on wetting with water to form anhydrous calcium sulphate.

A and R are both right, and R is the correct explanation for A.Plaster of Paris is a quick-setting gypsum plaster made out of a fine white powder... View Article

Which of the following terms are unitless? (i) Molality (ii) Molarity (iii) Mole fraction (iv) Mass percent

(Mass of solute/Mass of solution) / 100 = mass percentThe Mole Fraction is the proportion of a component's moles to the total number of... View Article

Which of the following statements are correct for carbenes? only one unshared electron is present in each orbital, there is only one unpaired electron, hybridisation of c is sp3, all of the above.

only one unshared electron is present in each orbital, there is only one unpaired electron, hybridisation of c is sp3, all of the above.... View Article

when a gas is compressed keeping temperature constant it results in

Gas is compressed at a fixed temperature. According to Boyle's law, the volume in which gas is travelling decreases while pressure rises. There... View Article