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