Answer:
+8 J/mol
Explanation:
The following were obtained from the question:
Mole of the compound = 3 moles
Heat Energy used = 24J
Hreaction =?
The heat of reaction is the energy released or absorb during a chemical reaction. It is can obtained mathematically by the following equation:
Hreaction = Heat energy/mole
With the above equation, we can easily find the Hreaction for the question given as follow:
Hreaction = Heat energy/mole
Hreaction = 24J / 3mol
Hreaction = 8 J/mol
Since the compound used the energy, the Hreaction is +8 J/mol
Answer:
Reasonable Second step- 
Explanation:
The given single step chemical reaction is as follows.

Suppose a two-step mechanism is proposed for this reaction,
The reaction occured in two steps they are as follows.


Answer:
This is the first answer,
winter solstice
The winter solstice occurs during the hemisphere's winter. In the Northern Hemisphere, this is the December solstice (usually December 21 or 22) and in the Southern Hemisphere, this is the June solstice (usually June 20 or 21).
and this is the second one,
the tilt of the Earth on its axis
Seasons change because of the tilt of the Earth and the planet's movement around the Sun. Did you know? It takes about 365.25 days for the Earth to orbit the Sun. We have leap years to make up for the extra ¼ day!
Answer:

Explanation:
Hello,
In this case, since a change in science is widely known to be considered as a subtraction between the the final and initial values of two measured variables and is represented via Δ, here the final density is 5.43 g/mL and the initial one was 3.21 g/mL, therefore, the change in density is:

Best regards.
Molal or molar? There is a difference