Explanation:
First thing first, you mistyped the specific heat of water, which should be
c
water
=
4.18
J
g
∘
C
Now, a substance's specific heat tells you how much heat is required to increase the temperature of
1 g
of that substance by
1
∘
C
.
In the case of water, you would need
4.18 J
to increase the temperature of
1 g
of water by
1
∘
C
.
Notice that your sample of water has a mass of
1 g
as well, which means that the only factor that will determine the amount of heat needed will be the difference in temperature.
The equation that establishes a relationshop between heat and change in temperature looks like this
q
=
m
⋅
c
⋅
Δ
T
, where
q
- heat absorbed
c
- the specific heat of the substance, in your case of water
Δ
T
- the change in temperature, defined as the difference between the final temperature and the initial temperature
Plug in your values and solve for
q
to get
q
=
1.00
g
⋅
4.18
J
g
⋅
∘
C
⋅
(
83.7
−
26.5
)
∘
C
q
=
239.096 J
Rounded to three sig figs, the answer will be
q
=
239 J
