An equilibrium exists between nitrosyl chloride, NOCl, nitrogen oxide, NO, and chlorine, Cl2
An equilibrium exists between nitrosyl chloride, NOCl, nitrogen oxide, NO, and chlorine, Cl2.
2NOCl(g) ⇌ 2NO(g) + Cl2(g)
Ammonia is a weak base.
(a) (i) Deduce the equilibrium constant expression for this reaction
(a) (ii) Explain the effect on the position of equilibrium and the value of Kc when pressure is decreased and temperature is kept constant
(a) (iii) 2.00 mol of NOCl was placed in a 1.00 dm3 container and allowed to reach equilibrium at 298 K. At equilibrium, 0.200 mol of NO was present. Determine the equilibrium concentrations of NOCl and Cl2, and hence calculate the value of Kc at this temperature
(a) (iv) The value of Kc is 1.60×10−5 at 318 K. State and explain whether the forward reaction is exothermic or endothermic
20.0 cm3 of hexane, C6H14, and 20.0 cm3 of pentan-1-ol, C5H11OH, were placed separately into two closed containers at 298 K and allowed to reach equilibrium
(b) (i) Compare the two liquids in terms of their boiling points, enthalpies of vaporization and vapour pressures
(b) (ii) Explain your answer given for part (b)(i)
(c) (i) Calculate the pH of a 1.50 moldm−3 solution of ammonia at 298 K to two decimal places, using Table 15 of the Data Booklet
(c) (ii) A buffer solution is made using 25.0 cm3 of 0.500 moldm−3 hydrochloric acid, HCl (aq), and 20.0 cm3 of 1.50 moldm−3 ammonia solution, NH3(aq).
Describe the meaning of the term buffer solution
(c) (iii) Determine the pH of the buffer solution at 298 K
(c) (iv) A 1.50 moldm−3 solution of ammonia is added to 25.0 cm3 of a 0.500 moldm−3 hydrochloric acid solution in a titration experiment.
Calculate the total volume of the solution at the equivalence point
(c) (v) Calculate the pH of the solution at the equivalence point, using Table 15 of the Data Booklet
(c) (vi) a suitable indicator for this titration, using Table 16 of the Data Booklet