Question

The combustion of 44.45 grams of a hydrocarbon gas mixture releases 2,649 kJ of heat. How much energy, in kWh, will the combustion of exactly one pound of this hydrocarbon gas produce? There are 453.592 g in 1 lb. Please express your answer to the appropriate number of significant figures. Your Answer:

Answer 1

Explanation:

It is given that 44.45 g of hydrocarbon gas produces 2649 kJ or $2649 \times 10^{3} J$ of heat.

Also here, 1 lb = 453.592 g.

Therefore, amount of energy released by 453.592 g of hydrocarbon gas will be calculated as follows.

              $\frac{2649 \times 10^{3} J \times 453.592 g}{44.45 g}$

             = $27.03 \times 10^{6} J$

It is known that 1 J = $2.778 \times 10^{-7} Kwh$.

Hence, $27.03 \times 10^{6} J$ = $27.03 \times 10^{6} J \times 2.778 \times 10^{-7} Kwh/J$

                              = 7.508 Kwh

Thus, we can conclude that the combustion of exactly one pound of this hydrocarbon gas produce 7.508 Kwh energy.