Question

Calculate the energy required to heat 769.0mg of graphite from −2.3°C to 19.9°C. Assume the specific heat capacity of graphite under these conditions is ·0.710J·g−1K−1 . Round your answer to 3 significant digits.

Answer 1

Given :

• the mass of graphite (m) = 769.0mg/1000= 0.769g

,

• ∆T = Tfinal-T initiatl = (19.9°C -(-2.3°C) = 22.2°C+273 =295.2K

,

• specific heat capacity of graphite = 0.710J·g−1K−1

We will use the following formula : and substitute the values above-

Q (heat) = m*C*∆T

= 0.769g *0.710J·g−1K−1 * 295.2K

=161.06705J

≈ 161.067 J ......(3 significant digits.)

• This means that the heat required is ,161.067 J, .