Calculate the standard enthalpy of formation of gaseous carbon
tetrafluoride (CF4) using the following thermochemical
information:
2 HF(g) H2(g) + F2(g) | H = +537 kJ | |
2 CF4(g) + 4 HF(g) C2H4(g) + 6 F2(g) | H = +2486.3 kJ | |
C2H4(g) 2 C(s) + 2 H2(g) | H = -52.3 kJ |
Calculate the standard enthalpy of formation of gaseous carbon
tetrafluoride (CF4) using the following thermochemical
information:
2 HF(g) H2(g) + F2(g) | H = +537 kJ | |
2 CF4(g) + 4 HF(g) C2H4(g) + 6 F2(g) | H = +2486.3 kJ | |
C2H4(g) 2 C(s) + 2 H2(g) | H = -52.3 kJ |
H = kJ
H = -680 kJ
Explanation
Reaction 1 : 2 HF (g) H2 (g) + F2 (g) : H1 = 537 kJ
Reaction 2 : 2 CF4 (g) + 4 HF (g) C2H4 (g) + 6 F2 (g) : H2 = 2486.3 kJ
Reaction 3 : C2H4 (g) 2 C (s) + 2 H2 (g) : H3 = -52.3 kJ
Desired reaction : C (s) + 2 F2 (g) CF4 (g)
Consider the operation : [2 * (Reaction 1) - (Reaction 2) - (Reaction 3)] / 2
This operation gives the desired reaction
H = [2 * (H1) - (H2) - (H3)] / 2
H = [2 * (537 kJ) - (2486.3 kJ) - (-52.3 kJ)]
H = (1074 kJ - 2486.3 kJ + 52.3 kJ) / 2
H = (-1360 kJ) / 2
H = -680 kJ
Calculate the standard enthalpy of formation of gaseous carbon tetrafluoride (CF4) using the following thermochemical information:...
Calculate the standard enthalpy of formation of gaseous carbon tetrafluoride (CF4) using the following thermochemical information: Calculate the standard enthalpy of formation of gaseous carbon tetrafluoride (CF4) using the following thermochemical information: H2(g)F2(g) 2 HF(g) 2 CF4(g)4 HF(g) C2H4(g) +6 F2(g) C2H4(g)2 C(s) 2 H2(g) AH -537 kJ AH 2486.3 kJ AH -52.3 kJ ΔΗ - kJ
Calculate the standard enthalpy of formation of gaseous hydrogen fluoride (HF) using the following thermochemical information: C2H4(g) + 6 F2(g) 2 CF4(g) + 4 HF(g) H = -2486.3 kJ CF4(g) C(s) + 2 F2(g) H = +680 kJ C2H4(g) 2 C(s) + 2 H2(g) H = -52.3 kJ H = ??? kJ
Calculate the standard enthalpy of formation of gaseous hydrogen fluoride (HF) using the following thermochemical information: C2H4(g) + 6 F2(g) 2 CF4(g) + 4 HF(g) H = -2486.3 kJ CF4(g) C(s) + 2 F2(g) H = +680 kJ C2H4(g) 2 C(s) + 2 H2(g) H = -52.3 kJ H = ___?kJ The answer is not -589.3
Calculate the standard enthalpy of formation of gaseous hydrogen fluoride (HF) using the following thermochemical information: C2H4(g) + 6 F2(g) 2 CF4(g) + 4 HF(g) (delta)H = -2486.3 kJ CF4(g) C(s) + 2 F2(g) (delta)H = +680 kJ 2 C(s) + 2 H2(g) C2H4(g) (delta)H = +52.3 kJ (delta)H =__________ kJ
Calculate the standard enthalpy of formation of gaseous carbon dioxide (CO2) using the following thermochemical information: 2 C(s) + H2(g) C2H2(g) H = +226.8 kJ 2 C2H2(g) + 5 O2(g) 4 CO2(g) + 2 H2O(l) H = -2599.3 kJ 2 H2O(l) 2 H2(g) + O2(g) H = +571.7 kJ H = _______kJ
Calculate the standard enthalpy of formation of gaseous acetylene (C2H2) using the following thermochemical information: 2 C2H2(g) + 5 O2(g) 4 CO2(g) + 2 H2O(l) H = -2599.3 kJ CO2(g) C(s) + O2(g) H = +393.5 kJ 2 H2O(l) 2 H2(g) + O2(g) H = +571.7 kJ H = kJ
Calculate the standard enthalpy of formation of gaseous carbon dioxide (CO2) using the following thermochemical information: 2 Ca(s) + O2(g) = 2 Cao(s) CaO(s) + CO2(g) = CaCO3(s) 2 C(s) + 2 Ca(s) + 3 O2(g) = 2 CaCO3(s) AH = -1270.2 kJ AH = -178.3 kJ AH = -2413.8 kJ AH = kJ
Calculate the standard enthalpy of formation of gaseous methane (CH4) using the following thermochemical information: CO2(g) + 2 H2O(l) CH4(g) + 2 O2(g) H = +890.4 kJ CO2(g) C(s) + O2(g) H = +393.5 kJ 2 H2O(l) 2 H2(g) + O2(g) H = +571.7 kJ
Calculate the standard enthalpy of formation of gaseous sulfur dioxide (S02) using the following thermochemical information: 2 Mgo(s) = 2 Mg(s) + O2(g) Mg(s) + S(s) = MgS(s) Mgs(s) + 2 Mgo(s) = 3 Mg(s) + SO2(g) AH = +1203.4 k) AH = -598.0 kJ AH = +1504.6 kJ AH = k]
Practice with Hess's Law and Standard Heats of Formation 1. (Example) The reaction C2H4 (g) + 6 F2 (g) → 2 CF4(g) + 4 HF (g) can be written as the sum of: C2H4 (9) ► 2 C(s) + 2 H2 (g) AH = -52.3 kJ/mol 2 C(s) + 4 F2 (9) ► 2 CF4(9) AH = -1360 kJ/mol 2 H2(g) + 2 F2 (g) → 4 HF (a) AH = -1074 kJ/mol C2H4(g) + 6 F2(g) → 2 CF4(g)...