Question

H2 (g) + Cl2 (g) 2HCl (g) ΔH = -185 kJ
endothermic or exothermic?

Answer 1

do you know what endothermic and exothermic mean?

Answer 2

endothermic absorbs heat
exothermic releases heat
right?

Answer 3

I can tell if its on a graph but it doesn't come with a graph.

Answer 4

By looking at the graph which one is endothermic reaction and which one is the exothermic reaction below?

remember exothermic reaction means that we've lost heat. so when we lose heat, the products are at a lower energy that than the reactants, that means they are more stable.

opposite is true for the endothermic. the reaction absorbs energy, meaning heat needs to be put into the reaction to make it go to the products. of course there's another topic here called spontanitety and that really tells us whether the reaction will happen not.

Answer 5

first one exothermic
the second one on the right endothermic
correct?

Answer 6

correct and how do you know?

Answer 7

remember another thing

the heat of reaction is

\[\Delta H = H_{products}-H_{reactants}\]

so when we take the difference in enthalpies from the products-reactants and


\[\Delta H = negative , exothermic; \Delta H = positive, endothermic \]