In calculating the change in enthalpy in a certain reaction, it is important to remember that it is the sum of the enthapy of formation for the substances involved in the reaction.
<span>CaO(s)+2HCl(aq)→CaCl2(aq)+H2O(l) ΔH= –186kJ
</span>Ca(OH)2(aq) → CaO(s)+H2O(l)<span> ΔH= 65.1 kJ
</span>Ca(OH)2(aq) + 2HCl(aq) → CaCl2(aq) + 2H2O(l) ΔH= -120.9 kJ
A. 2
trust me i used to so this in middle school
Answer:
Option A and D are correct.
Unstable species react rapidly.
Stable species do not react rapidly.
Explanation:
The complete question is attached to this solution.
The more stable a reactant is, the less reactive it will be. A stable reactant has a very stable structure in which it will avoid any perturbations. And for a reaction to occur, the bonds in the reactant must break down to form the products. A stable reactant has very strong bonds that aren't easy to break down, hence, reactions involving very stable reactants do not proceed rapidly.
And the more unstable a reactant specie is, the more rapidly it reacts. This is why the reaction involving the less stable isotope of carbon; Carbon-14 is very rapid. It is the same reason as explained above that is responsible for this. The bond between unstable species are not strong and are easily breakable, thereby leading to a quick reaction.
Hope this Helps!!!
Answer:
The log will float on the water because its density is lower than the liquid, so it will stay at the top due to Archimedes' principle.