s0melazyazn
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Problem
1.Calculate the heat required to melt 64.0 g of solid methanol, given that the molar enthalpy of fusion is 3.22 kJ/mol and the molar mass of methanol is 32.0 g.
2.If molar enthalpy of vaporization of ethanol is 38.6 kJ/mol, how many moles of ethanol are vaporized, when the required heat is 200.72 kJ?
3.Calculate the enthalpy change with the help of Hess’s law for the decomposition of hydrogen peroxide, (2H O (l) = 2H O(l) + O (g)), if the enthalpy of formation of water (2H (g) +O (g)) is –512KJ and vaporization of hydrogen peroxide (H O (l) = H (g) + O (g)) is 376 kJ.
4.Calculate the enthalpy change of the reaction 2CO(g) + 2NO(g) 2CO (g) +N (g) using thermochemical equations:
a)2CO(g) + O (g) 2CO (g)
b)2NO(g) N (g) + O (g)
The enthalpy of the equation a) is –566.0 kJ and the enthalpy of the equation b) is –180.6 kJ.
5.Calculate the standard enthalpy change of a reaction using the total enthalpies of the reactants and the products. The total enthalpy of the reactants is –912 kJ and the total enthalpy of the products is –82 kJ.
6.Calculate the enthalpy change of a reaction using the following values, enthalpy of reactant 1 = 404 kJ, enthalpy of reactant 2 = 432 kJ, enthalpy of product 1 = 218 kJ, enthalpy of product 2 = 74 kJ and enthalpy of product 3 = 199 kJ.
7.Calculate the enthalpy change of the reaction CH4 (g) + 2Cl2(g) CCl4 (l) + 2H2 (g), using thermochemical equations:
a)C(s) + 2Cl2 (g) CCl4 (l) = –128 kJ
b)CH4 (g) C(s) + 2H2 (g) = + 75 kJ
8.Determine S for the reaction
SO3(g) + H2O(l) H2SO4(l),
given the following entropies.
CompoundEntropy (J/mol•K)
SO3(g)256.8
H2O(l)70.0
H2SO4(l)156.9
1.Calculate the heat required to melt 64.0 g of solid methanol, given that the molar enthalpy of fusion is 3.22 kJ/mol and the molar mass of methanol is 32.0 g.
2.If molar enthalpy of vaporization of ethanol is 38.6 kJ/mol, how many moles of ethanol are vaporized, when the required heat is 200.72 kJ?
3.Calculate the enthalpy change with the help of Hess’s law for the decomposition of hydrogen peroxide, (2H O (l) = 2H O(l) + O (g)), if the enthalpy of formation of water (2H (g) +O (g)) is –512KJ and vaporization of hydrogen peroxide (H O (l) = H (g) + O (g)) is 376 kJ.
4.Calculate the enthalpy change of the reaction 2CO(g) + 2NO(g) 2CO (g) +N (g) using thermochemical equations:
a)2CO(g) + O (g) 2CO (g)
b)2NO(g) N (g) + O (g)
The enthalpy of the equation a) is –566.0 kJ and the enthalpy of the equation b) is –180.6 kJ.
5.Calculate the standard enthalpy change of a reaction using the total enthalpies of the reactants and the products. The total enthalpy of the reactants is –912 kJ and the total enthalpy of the products is –82 kJ.
6.Calculate the enthalpy change of a reaction using the following values, enthalpy of reactant 1 = 404 kJ, enthalpy of reactant 2 = 432 kJ, enthalpy of product 1 = 218 kJ, enthalpy of product 2 = 74 kJ and enthalpy of product 3 = 199 kJ.
7.Calculate the enthalpy change of the reaction CH4 (g) + 2Cl2(g) CCl4 (l) + 2H2 (g), using thermochemical equations:
a)C(s) + 2Cl2 (g) CCl4 (l) = –128 kJ
b)CH4 (g) C(s) + 2H2 (g) = + 75 kJ
8.Determine S for the reaction
SO3(g) + H2O(l) H2SO4(l),
given the following entropies.
CompoundEntropy (J/mol•K)
SO3(g)256.8
H2O(l)70.0
H2SO4(l)156.9