Liquid nitrogen is vaporised to form nitrogen gas. Complete the sentences below using one of the following options:
The graph below shows how the temperature of the nitrogen varied with time as it was heated.

A mass of 0.45 kg0.45\text{ kg}0.45 kg of liquid nitrogen was turned into nitrogen gas. The specific latent heat of vaporisation of nitrogen is 200 000 J/kg200\,000\text{ J/kg}200000 J/kg.
Calculate the thermal energy transferred to the nitrogen to turn it into gas.
Use the equation: thermal energy for a change of state=mass×specific latent heat\text{thermal energy for a change of state} = \text{mass} \times \text{specific latent heat}thermal energy for a change of state=mass×specific latent heat
The mass of the nitrogen gas was 0.45 kg0.45\text{ kg}0.45 kg and its volume was 0.36 m30.36\text{ m}^30.36 m3.
Calculate the density of the nitrogen gas.
Use the equation: density=massvolume\text{density} = \frac{\text{mass}}{\text{volume}}density=volumemass
Choose the unit from the following options: kg\text{kg}kg, m3/kg\text{m}^3\text{/kg}m3/kg, or kg/m3\text{kg/m}^3kg/m3.