What is the relationship between a chemical equation and a chemical reaction? What are reactants and products in a chemical equa
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The question is incomplete, here is the complete question.
A sample of ethanol , weighing 6.83 g underwent combustion in a bomb calorimeter by the following reaction:
If the heat capacity of the calorimeter and contents was 18.1 kJ/°C and the temperature of the calorimeter rose from 25.50°C to 36.73°C. What is the of the reaction?
<u>Answer:</u> The enthalpy of the reaction is -1355.1 kJ
<u>Explanation:</u>
To calculate the heat absorbed by the calorimeter, we use the equation:
where,
q = heat absorbed
c = heat capacity of calorimeter = 18.1 kJ/°C
= change in temperature =
Putting values in above equation, we get:
Heat absorbed by the calorimeter will be equal to the heat released by the reaction.
<u>Sign convention of heat:</u>
When heat is absorbed, the sign of heat is taken to be positive and when heat is released, the sign of heat is taken to be negative.
To calculate the number of moles, we use the equation:
Given mass of ethanol = 6.83 g
Molar mass of ethanol = 46 g/mol
Putting values in above equation, we get:
To calculate the enthalpy change of the reaction, we use the equation:
where,
q = amount of heat released = -203.26 kJ
n = number of moles = 0.15 moles
= enthalpy change of the reaction
Putting values in above equation, we get:
Hence, the enthalpy of the reaction is -1355.1 kJ