Question

An ancient copper coin was found to absorb 545.8 J of heat when the temperature increases 31.4 C°. The specific heat of copper is 0.387 J/g°C. What is the mass of the copper coin?

Answer 1

The mass of the copper coin is 44.9 g.

The formula for the heat absorbed by a substance is

`color(blue)(|bar(ul(color(white)(a/a) q = mcΔT color(white)(a/a)|)))" "`

where

`q` is the quantity of heat

`m` is the mass of the substance

`c` is the specific heat capacity of the material

`ΔT` is the temperature change

You can rearrange the formula to calculate the specific heat capacity:

`m = q/(cΔT)`

`m = (545.8 color(red)(cancel(color(black)("J"))))/(0.387 color(red)(cancel(color(black)("J·°C"^"-1")))"g"^"-1" × 31.40 color(red)(cancel(color(black)("°C")))) = "44.9 g"`

Wouldn't it have been easier to weigh the coin on a balance?