[填空题]
A 30-g ice cube at its melting poit,m6 i )+ wp3clkn4mrzgt/ud1nt is dropped into an insulated c f0/y8 -p)axxc tn1qspontainer of liquid nitrogen. How much nitrogen evaporates if it is at its boiling point of 77 K and has a latx ny-a81c 0 )ptxfps/qent heat of vaporization of $200\,kJ/kg$ Assume for simplicity that the specific heat of ice is a constant and is equal to its value near its melting point. kg