This is due todaystudy the graph below to answer the question. reaction a is an exothermic process and reaction b is an endothermic process because a. the enthalpy change of reaction a is lower than that of reaction b. b. δh is positive for reaction a and δh is negative for reaction b. c. the energy of activation of reaction a is lower than that of reaction b. d. δh is negative for reaction a and δh is positive for reaction b.

Answer is: D. ΔH is negative for reaction A and ΔH is positive for reaction B.

There are two types of thermochemical reactions:  

1) endothermic reaction (chemical reaction that absorbs more energy than it releases).

For example, ΔH(reaction) = 150 kJ/mol; this is endothermic reaction.

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).

For example, ΔH(reaction) = -225 kJ/mol; this is exothermic reaction.

the change in enthalpy = the total bonding energy for the products of a reaction - the bonding energy of the reactants.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

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