OCR A LEVEL JUNE 2022 CHEMISTRY A PAPER 3 EXAM QUESTION PAPER

OCR A LEVEL JUNE 2022 CHEMISTRY A PAPER 3 EXAM QUESTION PAPERThese questions are from different areas of chemistry. (a) Ammonia, NH3, and ammonium nitrate, NH4NO3, are compounds of nitrogen. (i) The boiling point of NH3 is –33 °C. The boiling point of NH4NO3 is 210 °C. Explain why there is a large difference in boiling points. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2] (ii) Two students discuss the oxidation numbers in ammonium nitrate, NH4NO3. One student claims that the two nitrogen atoms have the same oxidation number. The other student disagrees and claims that the nitrogen atoms have different oxidation numbers. Explain with reasons which student is correct. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1