When you crush a first-aid pack for an injured athlete and the pack gets cold, which of the following is true?
2 answers:
Answer: Option (d) is the correct answer.
Explanation:
A chemical reaction in which heat is released by the reactants is known as an exothermic reaction.
For example,
As energy is released, hence total energy of products is less than the total energy of reactants in an exothermic reaction.
On the other hand, a chemical reaction in which heat is absorbed by reactant molecules is known as an endothermic reaction.
For example,
As energy is absorbed, hence total energy of reactants is less than the total energy of products in an endothermic reaction.
Thus, we can conclude that when you crush a first-aid pack for an injured athlete and the pack gets cold, a chemical change has occurred, with energy being absorbed.
You might be interested in
Answer: Option (e) is the correct answer.
Explanation:
Chemical formula of a nitrate ion is and it acts as a strong oxidizing agent because it itself gets reduced easily.
As we know that an oxidizing agent tends to oxidize other substances by itself gaining electrons. As a result, there will occur a decrease in its oxidation state.
The oxidation number of nitrogen in is +5. So, it gains electrons and helps in oxidizing other substances.
Thus, we can conclude that the nitrate anion is a strong oxidizing agent.