2 A 1000 cm cubical box inside a perfectly insulating shield

2. A 1000 cm\' cubical box inside a perfectly insulating shield contains N2 at a pressure of 1.01 x 10* Pa and a temperature of 23.0 A 28 g block of copper at SSOC is placed in the box, then the perfectly insulating lid is quickly and tightly sealed. (Note that the copper displaces some air so the final volume of air in the box is 998 cm\'). A. What is the mass of nitrogen inside this box? B. what is the final temperature inside the box? The specific heat of N2 is 740 J/(kg K) and the specific heat of copper is 385 J/(kg K). C. What is the final pressure inside the box? D. Suddenly, the insulating shield is removed from all sides of the box. Assuming the box is a cube with perfect emissivity, what is the luminosity of the box? E. At what wavelength would we expect to find the peak of the blackbody spectrum of this box?

Solution

1) As PV=nRT so P is 1 atm and volume is 1 litre and R is 0.082 in lite atm/kelvin and t is 296 k now 1*1=n*0.082*296

so n comes to be 0.041 so n is mass/ molar mass

so mass = 0.041*28 is 1.15