Question

3.5 g of a hydrocarbon fuel is burned in a vessel that contains 250. grams of water initially at 25.00 C. After the combustion, the temperature of the water is 26.55 C. How much heat is evolved per gram of fuel burned?
1. 73.5 J/g
2. 1263 J/g
3. 463 J/g
4. 143 J/g
5. 1105 J/g
6. 1764 J/g
7. 26555 J/g
8. 511 J/g

Answer 1

Answer:

3.) 463 J/g

Explanation:

Heat given by the fuel is used to increase the temperature of the water

so it is given as

$Q = ms\Delta T$

here we will have

m = 250 g

$\Delta T = 26.55 - 25$

now we also know that

$s = 4186$

so we have

$Q = (0.250)(4186)(26.55 - 25)$

$Q = 1622.075 J$

so 3.5 g fuel gives above energy

so per gram of fuel will have total energy given as

$Q = \frac{1622.075}{3.5}$

$Q = 463.45 J/g$