Chemistry- Calorimetry

Question

How much heat (in joules) is used to heat a 25.68 gram sample of iron from 1.18 degrees Celcius to 100.00 degrees Celcius if the specific heat of Fe is 0.450 ^J/_g°C?

I use this formula q = mc(TF-TI) and I get 1143J but I don't if I did my math wrong since the answer needed 3 sig figs

Answer 1

Good eveing Elias, I hope this helps some.

If you are using the equation: q =mcΔT then you were doing your math correct.

m = 25.68g

c = 0.450 J/g°C

ΔT = 100-1.18 = 98.82°C

q = 25.68g(0.450 J/g°C)(98.82°C)

q = 1141.96392 J

To get this answer with 3 sig figs, write it in scientific notation by moving the decimal place 3 spaces to the left and rounding accordingly.

q = 1.14 x 10³ J