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At what temperature does ammonia freeze?

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Difference in molecular structure between ammonia/amines and quaternary ammonium ions — ammonia Ammonia and amines have a slightly flattened trigonal pyramidal shape with a lone pair of electrons above the nitrogen. In quaternary ammonium ions, this area is occupied by a fourth substituent.

Ammonia has a freezing point of −77.7 °C (−107.8 °F).12