Answer:
There is 96200 J or 96 kJ of heat released.
Explanation:
<u>Step 1: </u>Data given
Mass of helium = 250 grams
Temperature = 200 K
Temperature is raised by 74 K
The heat capacity of helium = 20.8 J/mol*K
Molecular weight for helium = 4 g/mol
<u>Step 2:</u> Calculate moles of Helium
Moles of Helium = mass of Helium / molar mass of helium
Moles of helium = 250 grams / 4g/mol
Moles of helium = 62.5 moles
<u>Step 3:</u> Calculate heat
Q = n*c*ΔT or
⇒ with Q = the heat released in Joule
⇒ with n = moles of helium = 62.5 moles
⇒ with c = the heat capacity of helium = 20.8 J/mol*K
⇒ with ΔT = the change in temperature = T2 - T1 = 74 K
Q = 62.5 mol * 20.8 J/mol*K * 74 K
Q = 96200 J = 96 kJ
Since the temperature is raised, this is an exothermic reaction. The heat is released.
There is 96200 J or 96 kJ of heat released.
