4. Compound X is a colourless liquid at room temperature, (a) A sample of pure X was slowly heated from -5.0 °C, which is below its melting point, to 90
*C, which is above its boiling point. Its temperature is measured every minute and the
results are represented on the graph.
F
90°C-
D
E

temperature
B
t°C
С
-5°C
time

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .