WATER at 1 Atmosphere

The table presents selected thermodynamic properties of water. Water at 0° can be either solid (with its properties) or liquid (with its properties). To list both sets of properties, 0° is notated as 0-°C and 0+°C. The temperatures, 0-°C, means 0°C but solid; 0+°C means 0°C but liquid.

Basic Thermodynamics ~ J. Pohl ©

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WATER at 1 Atmosphere

The table presents selected thermodynamic properties of water. Water at 0° can be either solid (with its properties) or liquid (with its properties). To list both sets of properties, 0° is notated as 0-°C and 0+°C. The temperatures, 0-°C, means 0°C but solid; 0+°C means 0°C but liquid.

Use the data to answer the questions asked below it.

Water at One Atmosphere
p (Ts(p))		-40°C	0-°C	0+°C	100-°C	100+°C	500°C
101.3 kPa (100)oC	v   u   h	1.08 -410 -411	1.09 -332 -333	1.00 0.10 0.10	1.04 418 419	1680 2505 2675	3534 3130 3488
v ~ cm3/g     u ~ J/g      h ~ J/g

1) What is the volume of 5 kilograms of water at 1 atmosphere and 500°C?

Solution:   V = mv(1atm, 500°C) = 5000g (3534 cm³/g) = 17.7m³

2) Three grams of liquid water and 5000cm³ of gaseous water coexist in equilibrium at one atmosphere. What is the temperature? What is the enthalpy, H?
♦  Phases of water that coexist at one atmosphere have the temperature, 100°C. The enthalpy is:

H = m_f h_f + m_g h_g

H = m_f h_f + (V_g/v_g) h_g

H = 3g(419 J/g) + [5000 cm³/1680 cm ³/g](2675 J/g)

H = 9218 J

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3) Determine the volume of 400 grams of steam at 1 atmosphere and a) 300°C. b) 167°C.
♦  300°C is a nice number because it is midway between the table entries, 100+°C and 500°C. The fast answer is V = m{[v(500°C) + v(100^o+°C]/2}. Below we show all steps of the interpolation.