Answer:
2,220 J
Explanation:
In order to be able to determine how much heat is required to increase the temperature of your sample of water from
35.0
∘C to 70.0 ∘C
, you need to know the value of water's specific heat.
As you know, 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.
Water has a specific heat of about
4.18
Jg∘C
. This tells you that in order to increase the temperature of
1 g
of water by 1∘C
, you need to provide it with 4.18 J
of heat.
Now, here's how you can think about what's going on here. in order to increase the temperature of
4.18 g
of water by 1
∘C, you would need 4.18
times more heat than water's specific heat value.
Likewise, in order to increase the temperature of 4.18 g
of water by 4.18
∘C
, you'd need(4.18×4.18)
times more heat than water's specific heat value.
In your case, you need to increase the temperature of 15.2 g of water by
35.0
∘C , which tells you that you're going to need (
15.2
×
35
)
times more heat than water's specific heat value.
Mathematically, this is expressed as
q
=
m
⋅
c
⋅
Δ
T
, where q - heat absorbed/lost
m - the mass of the sample
c
- the specific heat of the substance
Δ
T - the change in temperature, defined as final temperature minus initial temperature
Plug in your values to get
q
=
15.2 g
⋅
4.18
Jg ∘C⋅
(
70.0
−
35.0
) ∘
C
q= 2223.76 J
Rounded to three sig figs, the answer will be
q
=2,220 J
