The warmer road surface at the end of a sunny day is the black road because during the day it absorbed more radiation (sunlight) than the withe one
Answer:
-1815.4 kJ/mol
Explanation:
Starting with standard enthalpies of formation you can calculate the standard enthalpy for the reaction doing this simple calculation:
∑ n *ΔH formation (products) - ∑ n *ΔH formation (reagents)
This is possible because enthalpy is state function meaning it only deppends on the initial and final state of the system (That's why is also possible to "mix" reactions with Hess Law to determine the enthalpy of a new reaction). Also the enthalpy of formation is the heat required to form the compound from pure elements, then products are just atoms of reagents organized in a different form.
In this case:
ΔH rxn = [(2 * -1675.7) - (3 * -520.0)] kJ/mol = -1815.4 kJ/mol
3 valence electrons are transferred in the formation of the compound potassium nitride because nitrogen needs 3 valence electron to become stable, or to have the electron configuration of noble Gases.
Answer:
-) 3-bromoprop-1-ene
-) 2-bromoprop-1-ene
-) 1-bromoprop-1-ene
-) bromocyclopropane
Explanation:
In this question, we can start with the <u>I.D.H</u> (<em>hydrogen deficiency index</em>):
In the formula we have 3 carbons, 5 hydrogens, and 1 Br, so:
We have an I.D.H value of one. This indicates that we can have a cyclic structure or a double bond.
We can start with a linear structure with 3 carbon with a double bond in the first carbon and the Br atom also in the first carbon (<u>1-bromoprop-1-ene</u>). In the second structure, we can move the Br atom to the second carbon (<u>2-bromoprop-1-ene</u>), in the third structure we can move the Br to carbon 3 (<u>3-bromoprop-1-ene</u>). Finally, we can have a cyclic structure with a Br atom (<u>bromocyclopropane</u>).
See figure 1
I hope it helps!
According to the Law of Conservation of Energy, energy is neither created nor destroyed. It is an entity that's always existing in the environment. It takes different forms of energy. Among the choices, the best answer would be letter B. Chemical energy. The chemical energy originates from the energy within the muscles that are dormant. Once used, this chemical energy is transformed into mechanical energy by the action of pushing his foot on the ground.
