Question

What is the mass of a piece of iron that releases 179.85 joules of heat as it cools from 51.29 degrees Celsius to 31.42 degrees Celsius? The specific heat of iron is 0.450 J/gC; please answer to two digits after the decimal point.

Answer 1

20.11 g.

Step-by-step explanation:

What is given?

c (specific heat of iron) = 0.450 J/g °C.

Q (heat energy) = 179.85 J.

ΔT (change of temperature) = |31.42 °C - 51.29 °C| = 19.87 °C.

What do we need? Mass of iron (m)

Step-by-step solution:

Let's see the formula of specific heat:

`c=(Q)/(m\cdot\Delta T)`

Where c is specific heat, Q is heat energy, m is mass and ΔT is the change of temperature.

We just have to solve for 'm' to find the mass of iron and replace the given data that we have, like this:

`m=(Q)/(c\cdot\Delta T)=\frac{179.85\text{ J}}{0.450\text{ }(J)/(g\cdot\degree C)\cdot19.87\degree C}=20.11\text{ g.}`

The mass of the iron would be 20.11 g.