Question

1. If 22.5 grams of MnCl2 (MW: 126 g/mol) are dissolved in water & taken to a solution volume of 400.0 mL. What is the molarity of the solution in Cl- ions?

2. What is the value for ΔH rxn for a reaction with ΔG rxn = -42 kJ and ΔS rxn = 33 J/K?

3. The ΔS rxn for the reaction 2PCl3 (g) + O2 (g) ---> 2 POCl3 (g) is ?

    S (J/Kmol) PCl3:  312 O2: 205 POCl3: 325

4. The mg of KOH that are present in a 350 gram of a solution that is 21 ppm KOH?

Answer 1

[ime = loool Anso No. of moles of Mr Cl = mass of Hincla molecular weight (MW) o incle - 22.58 126 g/mol = 0.179 mol volume of solution = 400.0mL = 400.0L 1000 = 0.400 L no. of moles of Macla Molarity of MnCl2 solution = Volume of solution 0.179 mol 0.400 L = 0.448 M (mee = m) - Mncle in solution break as: - Mollz (aq.) → Morit(aq) + 2 C& Caz.) We can see in solution cľ ions are double of kniela Mntcaq.) - Mrilla in solution gives double moles of ce luns so ce lons molarity will be double of Malla molarity. [ce] - 2x [Mnlla] [c'] = 2 x 0.448 M [CE'] = 0.896 M Answers