Question

Below is a set of apparatus that was used to obtain a dry sample of sulphur(iv)oxide gas

1. Name;
   • Solid W 
   • The apparatus containing dilute hydrochloric acid 
2. State the role of Liquid Y 
3. Complete the diagram to show how the gas could have been collected 
4. A sample of sulphur(iv)oxide gas was passed through freshly prepared iron(III)sulphate solution. State and explain the observation made 
5. 50cm3 of 2M Hydrochloric acid was used during the above experiment. Determine the volume of sulphur(iv)oxide gas produced at r.t.p (molar gas volume = 24dm³) 

Answer 1

1.   
   • Sodium sulphite
   • Dropping funnel
2. Drying agent
3. 
   
4. Yellow  iron (III) sulphate  solution turned pale green sulphur (IV) oxide gas reduced iron (III) ions to iron (II) ions
5.    
   • Na₂SO_3(S) + 2HCl_(aq) → 2 NaCl_(aq)+SO_2(g) + H₂O_(l)
     moles of HCl
     2 moles  → 1000 cm³
     50 cm^{3
     (2×50)}/₁₀₀₀=¹⁰⁰/₁₀₀₀ = 0.1moles
     Mole ratio Hcl : SO₂
                          2 : 1 
     Moles of SO₂ = ¹/₂= 0.05moles
     1Mole → 24dm³
     moles ? = 1.2dm^{3
     2(0.05×24)}/₁