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Delta Heat for a Reaction

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Evaluate Delta H (standard) for the reaction below at 25 degress celcius

SiO2 (s) + 4HF (aq) >>>>>>> SiF4 (g) + 2H2O (l)

Delta H standard f (kj/mol) -910.9 -320.8 -1615 -285.8

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At one time, a common means of forming small quanities of oxygen gas in the laboratory was to heat KCLO3: 2KCLO2(s) --> 2KCL + 3O2 Delta H=-89.4KJ

At one time, a common means of forming small quanities of oxygen gas in the laboratory was to heat KCLO3:
2KCLO2(s) --> 2KCL + 3O2 Delta H=-89.4KJ

For this reaction, calculate the delta H for the formation of
a)0.855mol of o2
b) 10.75 g of KCL
c) The decomposition of KClo3 proceeds spontaneously when it is heated. DO you think that the reverse reaction, the formation of KCLO3 from KCL and O2, is likely to be feasible under ordinary condtions? Explain your answer

58
Under constant-volume conditons teh head of combustion of benzoic acid (HC7H5O2) is 26.38Kj.g. A 1.640g sample of benzoic acid is burned in a bomb calorimeter. The temperature of the calorimeter increases from 22.25 celcius to 27.20celcius.
a) What is the total heat capacity of the calorimeter?
b) A 1.320g sample of a new organic substance is combusted in the same calorimeter. The temperature of the calorimeter increased from 22.14 celcius to 26.82 degrees celcius. What is the heat of combustion per gram of the new substance
c) Supose that in changing sample, a portion of the water in the calorimeter were lost, In what way, if any, would this change the heat capacity of the calorimeter

62
From the enthalpies of the reaction
2H2 + O2--> 2H20 H= -483.6kj
3O2+2)3 H=+284.6Kj
Calculate the heat of the reaction
3H2 + O3-->3H20

74
Calcium Carbide (CaC2) reacts with water to form acetylene (C2H2) and Ca(OH)2. From the following enthalpy of reaction data and data in Appendix C, calculated H formation of CaC2

CaC2+2H20-->(Ca(OH2)2 +C2H2 delta H=-127.2Kj

Ca(OH)2=-986.2kj/mol
C2H2=226.77 kj/mol

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