2 Questions (1 Viewer)

[Shoesta]

What would be the increase in temperature of 500mL of water from the burning of 0.5 moles of ethanol?

What would be the increase in temperature of 10 grams of copper (specific heat of 0.38J/g.C^O from the combustion of 0.5 moles of ethanol?

 

[ml125]

1) Assuming the molar heat of combustion of ethanol to be 1367kJ/mol... you would first need to find the heat of reaction (ΔH) – which would be given by 1367x0.5 = 683.5kJ. You then sub this value into ΔH = mcΔT, using the mass and specific heat capacity for water to find the temperature.

683.5 x 10^3 = 500 x 4.18 x T
T = 683.5 x 10^3/(500 x 4.18)
T = 327K

2) From (1) it is known that the heat of reaction of the combustion of 0.5 moles of ethanol is 683.5kJ. Again, you sub this value into the equation ΔH = mcΔT using the given mass and heat capacity of copper.

683.5 x 10^3 = 10 x 0.38 x T
T = 683.5 x 10^3/(10 x 0.38)
T = 179868K

edit: answers look a bit ridiculous, if anyone could check my working it would be great HAHA half understandable since combusting a whole 0.5 moles but still a bit ???