The enthalpy change : -196.2 kJ/mol
<h3>Further explanation </h3>
The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation
The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)
(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)
The value of ° H ° can be calculated from the change in enthalpy of standard formation:
∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)
Reaction
2 H₂O₂(l)-→ 2 H₂O(l) + O₂(g)
∆H ° rxn = 2. ∆Hf ° H₂O - 2. ∆Hf °H₂O₂

Answer: I italicize for checking
- <em>Rocks are preserved through the process.</em>
- <em>Rocks change from one type to another.</em>
- <em>Different rock groups are interrelated.</em>
- Rocks change from one type to another in a specific order.
- <em>Environmental conditions influence a change in rock type.</em>
Explanation:
Rocks are preserved, as in you can't destroy them completely, but no, they don't <em>stay </em>the same they change.
It is softer than topaz and and it is softer than diamond (diamond has a Mohs hardness of 10, which is the highest value of the scale)
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.