An aqueous solution contains 2.8 mM of total ions. Part A If the solution is NaCl(aq), what is the concentration of chloride ion? Express your answer as a concentration to two significant figures. mM Cl (aq) Submit Request Answer Part B If the solution is FeCla (aq), what is the concentration of chloride ion? Express your answer as a concentration to two significant figures. mM Cl (a) Submit Request Answer
Answer
It is given in the question; the solution contains 2.8mM of total ions NaCl(a)-Na (a) a (aq) 1 mol of NaCl gives 1 mol of Na” and 1 mol of Cl. NaCl is a salt and therefore, completely ionizes into its ions in aqueous solution. Thus, the concentration of Na and Cl are same NaCl is dissolved in water. Therefore, the other ions involved is The concentration of total ions in the solution is 2.8 mM. The total ions in the solution are Na*. Cl, H* and OH-. Ionization constant of water is 10-14 .Therefore, the concentration of H and Cl- is 107 which is very low and may be neglected Therefore, the concentration of individual species is, 21 Na- 1-2.8 mM Na14 mM C1.4 mM FeCl3 (aq) > Fe” (aq) + 3CI (aq) 1 mol of NaCl gives 1 mol of Fe and 3 mol of CI. FeCl is a salt and therefore, completely ionizes into its ions in aqueous solution. Thus, the concentration of Cl- is 3 times the concentration of Fe The concentration of total ions in the solution is 2.8 mM. The total ions in the solution are Fe, 3Ci, H and OH. Neglecting the concentration of H and OH Therefore, the concentration of individual species is, Fe3 C2.8 mM 41 Fe” l = 2.8 mM CI(3 x 0.7) mM C2.1 mM
