Use specific Heat Capacity

Question

The specific heat capacity of gaseous oxygen is 0.916 J/g °C.

(a) Determine the amount of heat energy that is associated with heating a 10.9-g sample of gaseous oxygen from 22.2 °C to 37.9 °C.

Must be in J

(b) Calculate the final temperature reached when 907 J of heat is added to a 21.8-g sample of gaseous oxygen initially at 22.2 °C.

Must be in °C

Answer 1

a) q = mC∆T

q = heat = ?

m = mass = 10.9 g

C = specific heat = 0.916 J/gº

∆T = change in temperature = 37.9 - 22.2 = 15.7º

q = (10.9 g)(0.916 J/gº)(15.7º) = -157 J (negative sign because temperature went up -> exothermic rx)

b) q = mC∆T

q = 907 J

m = mass = 21.8 g

C = 0.916 J/gº

∆T = change in temp. = ?

Solve for ∆T = q/mC = 907 J/(21.8 g)(0.916 J/gº) = 4.54º

Since heat was added, the temperature will rise by this amount and final temp will be 22.2 + 4.54 = 26.7º