Choose the one alternative that best completes the statement or answers the ques

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Choose the one alternative that best completes the statement or answers the questions. Which of the following is a statement of Hess's law? The delta H of a process in the forward directions is equal to the delta H for the process direction. The delta H of a reaction depends on the physical states of the reactions and products. If a reaction is carried out in a series of steps, the delta H for the reaction will equal the sum of the enthalpy changes for the reverse direction. If a reaction is carried out in a series a steps, the delta H for the reaction will equal the product of the enthalpy changes for the individual steps. Identify the processes below which is (are) endothermic a match burns ice cubes solidify in the freezer rubbing alcohol feels cold on the skin 2 only 3 only 1, 2 and 3 2 and 3 only 1 and 2 only Then-reaction 4Al(s) + 3O_2 (g) rightarrow 2Al_2O_3(s); delta H^- = -3351kj is ______ and therefore heat is _______ by the reaction. exothermic, released exothermic, absorbed endothermic, absorbed endothermic, released thermoneutral, neither released nor absorbed The destruction of the ozone layer by chlorofluorocarbons (CFCs) can be described by the following reactions ClO(g) + O_3(g) rightarrow Cl(g) + 2O_2(g); delta H degree = -29.90 kj 2 O_3 rightarrow 3 O_2(g); delta H degree = 24. 28 kj Determine the enthalpy change for the following reaction Cl(g) + O_3(g) rightarrow ClO(g) + O_2(g); delta H degree = ? 41.99 kj 54.08 kj -5.72 kj -54.08 kj + 5.72 kj

Explanation / Answer

1)
Hess law is used to find H for complex reaction where H is sum od individual H
Answer: C

2)
When match burns , it produces energy
solidifying is requires energy
rubbing alcohol absorbs heat from skin
Answer: D

3)
since H is negative, it is exothermic reaction
Answer: A

i am allowed to answer only 1 question at a time

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