Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
D. action force and reaction forces are stated in his law
The correct answer is option C, 5.02 x 10²² carbon atoms
Atomic mass of C = 12 g/mol
According to Avogadro, 1 mole of C has 6.023 x 10²³C atoms
Now 1 mole of C is equal to 12 g
Therefore, 12 g of C = 6.023 x 10²³ C atoms
1 g of C = 
C atoms = 5.02 x 10²² C atoms
Answer:
See Explanation
Explanation:
According to the question, it is established that the pain caused by a lot of insect bites owes to the acidity of the insect bites.
If this is true, then there is an urgent need to neutralize the acidic insect bite using a basic substance.
Hence the pH of the creams used to treat insect bites should be basic(having a high pH).
2. The compound methene can not exist because it is supposed to be derived from the alkane called methane which contains only one carbon atom.
In order to form an alkene, there must be a double bond between two carbon atoms. This is not possible because there is only one carbon atom in the hypothetical methene. Hence, a compound named methene cannot exist.
Answer: B) calcium nitrate
