Assume that coal is essentially all carbon and has a density of 1.5 g/mL.1. How much heat is produced if a piece of coal 7cm x 5 cm x 6 cm undergoes complete combustion by the following reaction:
C ₍_s₎ + O₂ ₍_g₎ $\rarr$ CO₂ ₍_g₎; $\Delta$ H = -394 kJ2.
What mass of water could be heated from 25°C to 100°C with this amount of heat?
( $\Delta$ H_rxn = $\Delta$ H_products- $\Delta$ H_reactants; $\Delta$ H_rxn = Bond broken - Bonds made)

Question

Assume that coal is essentially all carbon and has a density of 1.5 g/mL.1. How much heat is produced if a piece of coal 7cm x 5 cm x 6 cm undergoes complete combustion by the following reaction:
C ₍_s₎ + O₂ ₍_g₎

\rarr

CO₂ ₍_g₎;

\Delta

H = -394 kJ2.
What mass of water could be heated from 25°C to 100°C with this amount of heat?
(

\Delta

H_rxn =

\Delta

H_products-

\Delta

H_reactants;

\Delta

H_rxn = Bond broken - Bonds made)

Quizplus · Accepted Answer

The heat produced by the combustion of coal is equal to the enthalpy change of the reaction, which is -394 kJ. This heat can be used to raise the temperature of water. The amount of water that can be heated from 25°C to 100°C with this amount of heat is:Q = m * C * $\Delta$Twhere:Q is the heat energy (in Joules)m is the mass of water (in grams)C is the specific heat capacity of water (4.184 J/g°C)$\Delta$T is the change in temperature (in °C)Solving for m, we get:m = Q / (C * $\Delta$T)= -394 kJ / (4.184 J/g°C * 75°C)= 3.3 x 10^4 gTherefore, the correct answer is A) -1.0 x10^4 kJ, 3.3 x10^4g of H2O.

Assume That Coal Is Essentially All Carbon and Has a Density