How many kilojoules are required to raise the temperature of a 2.119 g sample of iron from 25.0C to 35.0C? Iron has a specific heat of 0.450 J/j*C.

Question

The correct answer listed is 0.032; however, we keep getting 0.01 once rounded to two digits in the decimal.

Answer 1

Let's see if I get 0.032 or 0.01

q = mC∆T

q = heat = ?

m = mass = 2.119 g

C = specific heat = 0.450 J/gº (not J/jº)

∆T = change in temperature =10.0º

q = (2.119)(0.450)(10.0)

q = 9.5455 J x 1 kJ/1000 J = 0.0095455 kJ = 0.00955 kJ (rounded to 3 sig.figs.)

If you round it to 2 decimal places, you do have 0.01 kJ.