Question

A student runs two experiments with a constant-volume "bomb" calorimetercontaining 1400. g of water (see sketch at right).libraryequaliy mean is have sam...x Monroe County Library Sy...S Rosa Parks, an African Am...final 6hw5AutFirst, a 5.000 g tablet of benzoic acid (C6H5CO₂H) is put into the "bomb" andburned completely in an excess of oxygen. (Benzoic acid is known to have a heat ofcombustion of 26.454 kJ/g.) The temperature of the water is observed to rise from13.00 °C to 32.28 °C over a time of 10.7 minutes.Next, 4.900 g of ethane (C₂H6) are put into the "bomb" and similarly completelyburned in an excess of oxygen. This time the temperature of the water rises from13.00 °C to 44.56 °C.Use this information, and any other information you need from the ALEKS Dataresource, to answer the questions below about this reaction:2C₂H(g) + 70₂(g) → 4CO₂(g) + 6H₂O(g)2stirrerIs this reaction exothermic, endothermic, or neither?0thermometerchemical reaction"bomb"A "bomb" calorimeter.If you said the reaction was exothermic or endothermic, calculate the amount of heat that wasreleased or absorbed by the reaction in the second experiment.Be sure any of your answers that are calculated from measured data are rounded to the correct number of significant digits.Note for advanced students: it's possible the student did not do these experiments sufficiently carefully, and the values youcalculate may not exactly match published values for this reaction.exothermic

Answer 1

The calorimeter is an equipment that allows to measure the heat released or absorbed during a chemical reaction.

To make the calculations we are going to assume that there are no heat losses to the environment and that all the heat released by the chemical reaction is absorbed by the water.

I say that it is absorbed by the water because we are told for both reactions that the water increases its temperature. This is an indication that the reaction is exothermic, that is to say that the reaction releases heat and this heat is absorbed by the water causing the temperature to increase.

So for the first answer, it will be Exothermic.

Now, to calculate the heat released by the reaction we will apply the following equation:

`Q=mCp\Delta T`

Where,

Q is the absorbed heat by the water

Cp is the specific heat of water, 4.186kJ/g°C

m is the mass of water. 1400g

dT is the difference of temperature. Final temperature-Initial temperature

So, the heat absorbed by the water will be:

`Q=1400g*4.186(J)/(g\degree C)*(44.56\degree C-13.00\degree C)`
`Q=1.849*10^5J=185.0J`

The heat absorbed by the water will be greater than the heat released by the reaction. So, the second answer will be 185.0kJ

Now, to find the heat per mole of ethane, we must divide the total heat released by the number of moles of ethane. The moles of ethane will be equal to the grams of ethane divided by its molar mass.

`\begin{gathered} molC_2H_6=4.900g*(1molC_2H_6)/(MolarMass,gC_2H_6) \\ molC_2H_6=4.900g*(1molC_2H_6)/(30.07gC_2H_6)=0.1630molC_2H_6 \end{gathered}`

So, the heat released by mol of ethane will be:

`Heat/molC_2H_6=(185.0kJ)/(0.1630molC_2H_6)=1135kJ/mol`

The third answer will be: 1135kJ/mol