Heat capacity of NaNO2

Heat capacity in solid state was for the sodium nitrite (NaNO2) measured by using two types of calorimeters. The measurements were performed in the temperature range 273.15–583.15 K. Three phase changes were observed in this temperature range – one melting and two transitions between different structural modifications. Concerning the transitions between structural modifications, the first was observed at 437.2 ± 0.1 K and the second was found at 438.7 ± 0.1 K. Temperature of melting was then determined to be 553.2 ± 0.2 K with the corresponding heat of fusion being equal to 13.9 ± 0.1 kJ mol−1.