Recent questions tagged chemical-equilibrium

Description : What is solubility product?

Last Answer : The product of molar solubilities of the ions of weak electrolyte at equilibrium stage is called solubility product. It is represented by Ksp

Description : What is common ion effect?

Last Answer : The decrease in ionization of a weak electrolyte by adding another strong electrolyte having common ion.e.g ionization of NaCl is decreased by passing HCl through NaCl solution.

Description : How can you co–relate Ka with Kc?

Last Answer : Ka is dissociation constant of an acid while Kc is the equilibrium constant suppose an acid HA Ionize as HA + H2O  H3O+ + A– Kc = concentration of [H2O] almost remains constant so we can write. Kc = Kc [H2O] = ka Ka =

Description : A buffer consists of a weak acid and is salt.

Last Answer : (i) CH3COOH + CH3COONa (ii) C6H5COOH + C6H5COONa (iii) H2CO3 + NaHCO3 (iv) H3PO3 + NaH2PO4

Description : How can you purify NaCl by common ion effect?

Last Answer : The impurities present in the common salt are CaCl2 MgCl2 and Na2SO4 in it. These impurities can be removed by common Ion effect. For this purpose a saturated solution of NaCl is prepared. Then ... electrolyte than NaCl Ionization of NaCl is suppressed by passing HCl gas and it is precipitated out.

Description : Prove that Kw is ionic product of water and its value is 1 x 10–14 at 25o.

Last Answer : Water undergoes self ionization as 2H2O  H3O+ + OH– or H2O  H+ + OH– Kc [H2O] = [H+] [OH–] Kw = [H+] [OH–] At 25oC the value of Kw ionic product have been measured. Its value is 1 x 10–14.

Description : What is the relationship b/w kc, kp kc & kn?

Last Answer : These four parameters are related as. Kp = Kc (RT)n = Kx (P)n = Kn When mole of products are reactant are equal i.e. n = 0 their Kp = kc = dx = kn

Description : How the change in pressure at equilibrium position effect the following reaction? PCl5 PCl3 + Cl2

Last Answer : According to Le–chatlier’s principle, by increasing pressure the reaction will move toward less number of moles. In the above reaction, by increasing pressure the reaction will move in backward direction.

Description : A catalyst does not change the position of equilibrium but this equilibrium position approach earlier. Why?

Last Answer : A catalyst decrease the energy of activation required by reacting substance so the position of equilibrium reaches earlier.

Description : What are optimum conditions for the formation of NH3 by Haber’s process? N2(g) + 3H2(g) 2NH3(g) H = -92.46 kJ/m

Last Answer : (i) As the reaction is exothermic max yield is obtained at low temp. (ii) By applying pressure, more product is obtained. According four moles of reactants produce two moles of product so by applying ... (vi) Rate of reaction can also be increase with the help of catalyst like iron or iron oxide.

Description : How value of Kc can help to predict the extent to which a chemical reaction can take place?

Last Answer : The extent of reaction depends upon the magnitude of Kc. i.e. (i) Very small value of Kc: when Kc is very small the forward reaction will not occur to an appreciable extent ... neither very large nor very small, the equilibrium mixture contains appreciable amounts of both reactant and products.

Description : How Kc can be applied to calculate direction of chemical reaction?

Last Answer : (i) If < Kc Then the reaction will proceed in the forward direction until the equilibrium is established. (ii) If > Kc Then the reaction will proceed in the backward direction until the equilibrium is established. If = kc Then the reaction is already in equilibrium.

Description : What is buffer capacity?

Last Answer : The amount of acid or base which a buffer can absorb without significant charge in PH is called buffer capacity. Buffer capacity is the ability of buffer to resist the change in its PH value.

Description : Discuss the factors on which buffer PH depends.

Last Answer : PH of buffer depends upon two factors. (i) Pka or ka value of an acid (ii) Concentration of salt and acid taken for the buffer.

Description : Why we need buffer solution in daily life?

Last Answer : Buffers can resist the charge of its PH value therefore they are required in chemical analysis, pharmaceuticals, electroplating, photography, beverage industry, microbiology molecular biology, soil science and in quantitative ... PH 7.35. If it decreases upto 7 or goes upto 8 death may occur.

Description : What are conjugate acid and bases?

Last Answer : When an acid is dissolved in water it will form H3O+ ions and an anion the anion of an acid is called conjugate base and H3O+ is called conjugate acid e.g. CH3OOH + H2O H3O+ + CH3COO– Acid Base Conjugate acid Conjugate base

Description : Define Le–Chatlier’s principle.

Last Answer : If a system in equilibrium is disturbed at equilibrium it will move in that direction where change is minimized.

Description : What are reversible reaction?

Last Answer : Those reactions in which the reactants products are converted into each other under same set of conditions.

Description : What is meant by state of chemical equilibrium?

Last Answer : The state of reversible reaction, in which forward and reverse rates are equal.(Rf=Rr)

Description : What is weak electrolyte?

Last Answer : A compound which is only partially ionized in aqueous solution is called as weak electrolyte.e.g CH3COOH(Acetic aci)