Answer:
Density of aluminum is 2.699 g/cm^3
Explanation:
Density of a given material can be defined as the mass of the substance present in a unit volume. Mathematically it can be expressed as:
Units: g/cm^3 or kg/m^3
Aluminum (Al) is one the lightest element and is known to have a density of 2.699 g/cm^3
Answer:
Final temperature: 659.8ºC
Expansion work: 3*75=225 kJ
Internal energy change: 275 kJ
Explanation:
First, considering both initial and final states, write the energy balance:
Q is the only variable known. To determine the work, it is possible to consider the reversible process; the work done on a expansion reversible process may be calculated as:
The pressure is constant, so: (There is a multiplication by 100 due to the conversion of bar to kPa)
So, the internal energy change may be calculated from the energy balance (don't forget to multiply by the mass):
On the other hand, due to the low pressure the ideal gas law may be appropriate. The ideal gas law is written for both states:
Subtracting the first from the second:
Isolating :
Assuming that it is water steam, n=0.1666 kmol
ºC