Friday, 7 August 2015

9701 MCQ Solution 76

Question 76: [Inorganic > Group 7]


Why is the addition of concentrated sulphuric acid to solid potassium iodide unsuitable for the preparation of hydrogen iodide?
1 Hydrogen iodide is not displaced by sulphuric acid. 2 Iodide ions are oxidised to iodine. 3 The product is contaminated by sulphur compounds.

Reference: Past Exam Paper -June 2003 Paper 1 Q36

Solution 76:

Answer: C.

Statement 1 is false because sulphuric acid is a stronger oxidizing agent than hydrogen iodide so iodine can be displaced by sulphuric acid
Statement 2 is true as H2SO4 displaces HI to H2S and I2 and H2O
Statement 3 is true as there are sulphur compounds present, H2S and SO2

No comments:

Post a Comment

Include ONLY the reference.
Comments will only be published after moderation