Answer: C
Explanation:
In endothermic reactions, enthalpy is positive, and in exothermic reactions, enthalpy is negative, So, if enthalpy is positive, then it is an endothermic reaction, and hence is required for the reaction to occur.
Answer:
Analytical Groups I and II
Explanation:
Precipitation reactions happen when anions and cations in aqueous solution mix together to form an insoluble ionic solid which is now referred to as a precipitate.
Whether or not a type of reaction like that takes place can be determined by utilizing the solubility principles for common ionic solids.
Answer:
Bleach and seawater are identified wrong.
Explanation:
Acids have an pH that is lower than 7 and bases have a pH of higher than 7 and (pH 7 is neutral)
We can observe from the table that bleach has a pH of 13 which is higher than 7 and shows basic characteristics
As for seawater the table shows it has a pH of 8 which is also a base. Therefore the answer is 3rd option "Bleach and seawater should be identified as bases".
A
nswer: -
C. Energy is released by the reaction
Explanation:-
An exothermic reaction is one in which during the progress of the reaction heat is evolved.
So energy is released by the reaction.
It cannot be created as energy is neither created nor destroyed as per the Law of conservation of energy. Energy is not transferred either.
The energy released during the progress of the reaction originates from the chemical bonds of the reactants as they break during their conversion into products.
Atomic number is less than 11
