At constant pressure, the combustion of 5.00 g of C2H6(g) releases 259 kJ of heat. What is ΔH for the reaction given below? 2 C2H6(g) + 7 O2(g)–> 4 CO2(g) + 6 H2O(l). Hint: Convert 5.0 grams to moles (divide by molar mass). Divide 259 kJ by your answer to get kJ/mole reacted. Next, multiply by 2 since there are 2 C2H6(g) in the balanced reaction. Group of answer choices2155 kJ1800 kJ3108 kJ5168 kJ
Question
At constant pressure, the combustion of 5.00 g of C2H6(g) releases 259 kJ of heat. What is ΔH for the reaction given below? 2 C2H6(g) + 7 O2(g)–> 4 CO2(g) + 6 H2O(l). Hint: Convert 5.0 grams to moles (divide by molar mass). Divide 259 kJ by your answer to get kJ/mole reacted. Next, multiply by 2 since there are 2 C2H6(g) in the balanced reaction. Group of answer choices2155 kJ1800 kJ3108 kJ5168 kJ
Solution
First, we need to convert the 5.00 g of C2H6 to moles. The molar mass of C2H6 is approximately 30.07 g/mol. So, we divide 5.00 g by 30.07 g/mol to get approximately 0.166 moles of C2H6.
Next, we need to find out how much heat is released per mole. We know that the combustion of 5.00 g of C2H6 releases 259 kJ of heat. So, we divide 259 kJ by 0.166 moles to get approximately -1560 kJ/mol.
The balanced chemical equation shows that 2 moles of C2H6 are involved in the reaction. Therefore, we multiply -1560 kJ/mol by 2 to get -3120 kJ for the ΔH of the reaction.
So, the closest answer to -3120 kJ is -3108 kJ. Therefore, the ΔH for the reaction is approximately -3108 kJ.
Similar Questions
When 0.250 mol of CH4(g) reacts with excess Cl2(g) at constant pressure according to the chemical equation shown below, 177 kJ of heat are released. Calculate the value of ΔH for this reaction, as written. 2 CH4(g) + 3 Cl2(g) –> 2 CHCl3(l) + 3 H2(g) Group of answer choices-1616 kJ-1716 kJ-1516 kJ-1416 kJ
Question 16Calculate the standard enthalpy of combustion for the following reaction:C6H12O6(s) + 6O2(g) --> 6CO2(g) + 6H2O(l)
The heat of combustion of C8H18, is 5509 kJ/mol. What is the heat of combustion of C8H18, in units of kJ/g? Group of answer choices24.59 kJ/g48.29 KJ/g628475 kJ/g48290 kJ/g
If enthalpies of formation of C2H4( g),CO2( g) and H2O(l) at 25∘C and 1 atm pressure are 52,394 and −286 kJ/mol respectively, the change in enthalpy for combustion of C2H4 is equal to
Select the correct coefficients to balance the equation showing complete combustion of C5H12. ...C5H12(l)+ ...O2(g) → ...CO2(g) + ...H2O (g)
Upgrade your grade with Knowee
Get personalized homework help. Review tough concepts in more detail, or go deeper into your topic by exploring other relevant questions.