A scientist measures the standard enthalpy change for the following
reaction to be -613.2 kJ :
P4O10(s) + 6
H2O(l)-->4H3PO4(aq)
Based on this value and the standard enthalpies of formation for
the other substances, the standard enthalpy of formation of
H3PO4(aq) is kJ/mol.
Calculate (using bond energies) the heat of reaction
(per mole of CO, in KJ/Mol) for
the combustion of CO into CO2. Balance and do not round
final answer
Calculate (using bond energies) the heat of reaction
(per mole of
C2H2
in KJ/Mol) for the combustion of
C2H2 into CO2 and water. Balance
and do not round final answer
Use average bond energies to estimate the enthalpy
changes of the following reactions: a. N2(g) + 3 H2(g) -> 2
NH3(g) b. N2(g) + 2 H2(g) -> H2NNH2(g) c. 2 N2(g) + O2(g) ->
2 N2O(g)
a) The standard enthalpy change for the following reaction is
-270 kJ at 298 K.
2HCN (g) --> 2 C(s, graphite) + H2 (g) + N2 (g)
ΔH° = -270 kJ
What is the standard enthalpy change for this reaction at 298
K?
C (s, graphite) + 1/2 H2(g) + 1/2 N2(g) ---> HCN(g)
_______ kJ
A.) The standard enthalpy change for the following reaction is
359 kJ at 298 K.
PbCl2(s) ----> Pb(s) +
Cl2(g) ΔH° = 359
kJ
What is the standard enthalpy change for this reaction at 298
K?
Pb(s)
+ Cl2(g) ---->
PbCl2(s)
__________ kJ
B.) The standard enthalpy change for the following reaction is
-602 kJ at 298 K.
Mg(s)
+ 1/2 O2(g)
----> MgO(s) ΔH° =
-602 kJ
What is the standard enthalpy change for the reaction at 298
K?
2...
The standard enthalpy change for the following reaction is -170
kJ at 298 K. 2 Cu(s) + 1/2 O2(g) Cu2O(s) ΔH° = -170 kJ What is the
standard enthalpy change for the reaction at 298 K? 4 Cu(s) + O2(g)
2 Cu2O(s)
A student determines the heat of dissolution of solid cobalt(II)
chloride using a coffee-cup calorimeter of negligible heat
capacity. When 1.33 g of CoCl2(s) is dissolved in 111.00 g of
water, the temperature of the solution increases from...
For the reaction
A(aq) ---> B(aq)
the change in the standard free enthalpy is 2.59 kJ at 25
oC and 4.73 kJ at 45 oC. Calculate the value
of this reaction's equilibrium constant at 75 oC.
2.Calculate the specific enthalpy change in kJ / kg-C of the
following processes:
a) cyclohexane gas in a process from T0 = 300C to Ft= 900 C
b) hydrocyanic acid gas from T0 = 900C to Ft = 300 C.
Which of the two processes requires more energy? Which one would
you use to heat a stream of 100mol / h water that must enter a
heater at 25ºC and leave at 80ºC? Would it reach you?
#1. Estimate ΔH for the reaction using bond dissociation
energies. Give your answer in kcal. C6H12O6 has five C−C bonds,
seven C−H bonds, seven C−O bonds, and five O−H bonds.
#2. Is the reaction exothermic or endothermic?
#3. The following equation shows the conversion of aluminum
oxide (from the ore bauxite) to aluminum:
2Al2O3(s)→4Al(s)+3O2(g),
ΔH = +801.0 kcal
----> a. Is the reaction
exothermic or endothermic?