John R. answered • 04/07/19
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Note the energy released is given in KJ per mole, so the 1000 g of octane (C8H18) must be converted into moles, then multiplied by 5430 to get the heat released in KJ.
J.R. S.
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1000 g octane x 1mole/114.2 g x 5430 kJ/mole = 47,548 kJ, but if you use the 1 significant figure from the 1000 g, the answer would be 50,000 kJ. Rounded to 4 sig. figs would be 47550 kJ
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04/07/19
John R.
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I got a slightly different answer of 47538 (typo?) using 12.01 amu for C and 1.008 amu for H, but J.R. and I agree to 3 s.f. It is correct to use 1 s.f. for the amounts as shown, but I have noticed inconsistencies in the use of s.f.s within texts, different teachers, and assigned problems on computers. Check with your teacher if you having any questions about how many should be reported in differing contexts.
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04/07/19
Hsjsjsjsj N.
THANK YOU!! That is what I did but did not get the correct answer. Could you please list the answer?04/07/19