Which statement is true about the potential energy diagram for an exothermic reaction? the products have less potential energy than reactants. the energy value remains the same throughout the diagram. the graph starts at a lower energy value and ends at a higher energy value. the potential energy of the products is equal to the potential energy of the reactants

The products have less potential energy than reactants.

Explanation:

For an exothermic reaction; the potential energy of the products is less than that of reactants.

Since, ΔH = Pot. energy of products - Pot. energy of reactants.

and it must be negative value.

The attached image shows also the potential energy diagram of an exothermic reaction.

So, the right choice is The products have less potential energy than reactants.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"

a