Question

The heat of combustion of ethane is -337.0kcal at 25 degrees celsius. what is the heat of the reaction when 3g of ethane is burnt completely​

Answer 1

Q = -33.6kcal .

Step-by-step explanation:

Hello there!

In this case, according to the equation for the calculation of the total heat of reaction when a fixed mass of a fuel like ethane is burnt, we can write:

`Q=n*\Delta _cH`

Whereas n stands for the moles and the other term for the enthalpy of combustion. Thus, for the required total heat of reaction, we first compute the moles of ethane in 3 g as shown below:

`n=3g*(1mol)/(30.08g)=0.1mol`

Next, we understand that -337.0kcal is the heat released by the combustion of 1 mole of ethane, therefore, to compute Q, we proceed as follows:

`Q=0.1mol*-337.0(kcal)/(mol)\\\\Q=-33.6kcal`

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