Using the titration formula, we get that:
(concentration of HBr)(25)=(0.5)(15.3)
This means the molar concentration of HBr is (0.5)(15.3)/25 = 0.31 M
Correct Answer: C<span>a(s) + 2H2O(ℓ) → Ca(OH)2(aq) + H2(g)
Reason:
A reaction (</span>transmutation) is said to be spontaneous if it occurs on it's own, without any external stimulus. For spontaneous reaction, change in free energy (ΔG) is negative.
Among the given reactions, Ca(s) + 2H2O(ℓ) → Ca(OH)2(aq) + H2(g) occurs on its own with supplying external energy. Hence, it is a spontaneous reaction. Further, it is an exothermic reaction. So during the reaction heat is given out by the system.
On other hand, reaction: <span>2KClO3(s) → 2KCl(s) + 3O2(g) is a decompostion reaction. For occurrence of reaction, heat has to be supplied to system. Hence, this reaction is non-spontaneous in nature. </span>
Answer:
Substances that absorb energy in the form of heat are
b)endothermic.
hope it helps :)
