Answer: The final temperature of the water is
.
Explanation:
We know that molar mass of
is 78 g/mol. And, the amount of heat produced when 2 mol of
burns is 6542 KJ.
This means that,
= 156 g of
burns, heat produced is 6542 kJ.
Therefore, heat produced (Q) by burning 7.3 g of
is as follows.
![\frac{6542 \times 7.3 g}{156 g}](https://tex.z-dn.net/?f=%5Cfrac%7B6542%20%5Ctimes%207.3%20g%7D%7B156%20g%7D)
= 306.13 kJ
or, = 306130 J (as 1 KJ = 1000 J)
For water, mass is given as 5691 g and specific heat capacity of water is 4.186
.
So, we will calculate the value of final temperature as follows.
Q = ![m \times C \times (T_{f} - T_{i})](https://tex.z-dn.net/?f=m%20%5Ctimes%20C%20%5Ctimes%20%28T_%7Bf%7D%20-%20T_%7Bi%7D%29)
306130 J =
![(T_{f} - 21)^{o}C = \frac{306130 J}{23822.53 J/^{o}C}](https://tex.z-dn.net/?f=%28T_%7Bf%7D%20-%2021%29%5E%7Bo%7DC%20%3D%20%5Cfrac%7B306130%20J%7D%7B23822.53%20J%2F%5E%7Bo%7DC%7D)
= 12.85 + 21
= ![33.85^{o}C](https://tex.z-dn.net/?f=33.85%5E%7Bo%7DC)
Thus, we can conclude that the final temperature of the water is
.