For 5.0 g of a substance initially at 30°C with a heat capacity of 0.40 J/g°C, what will be its final temperature if q=-35 J?

Answer 1

For this problem, we can use the general equation q = mC∆T

q = heat = 35 J

m = mass = 5.0 g

C = specific heat = 0.40 J/g/deg

∆T = change in temperature = ?

35 J = (5.0 g)(0.40 J/g/deg)(∆T)

∆T = 35 J / (5.0 g)(0.40 J/g/deg)

∆T = 17.5 degrees - this is the CHANGE in temperature.

Since q has a positive value of + 35 J, we know the substance has absorbed heat (endothermic), so we must add 17.5º to the initial temperature.

Final temperature = 30º + 17.5º = 47.5ºC