<span>Hess' Law states that the enthalpy change in a reaction can be calculated from the enthalpy changes of reactions that, when combined, result in the desired reaction.
For example, to check the enthalpy change that occurs when benzene undergoes incomplete combustion to water and carbon monoxide is not an easy task, because the products invariably contain CO2. However, by combining the reactions of the complete combustion of benzene and the combustion of CO, you can get the reaction you want.
Reaction wanted: 2C6H6 + 9O2 → 12CO + 6H2O
Reactions provided: 2C6H6 + 15O2 → 12CO2 + 6H2O and 2CO + O2 → 2CO2, and their associated ΔH.
Rearrange the reactions so that, when they add up, they result in the wanted reaction.
2C6H6 + 15O2 → 12CO2 + 6H2O (leave as is; no changes to ΔH)
12CO2 → 12CO + 6O2 (reverse and multiply by 6; this changes the sign of ΔH and multiplies it by 6)
Added up, it will result in 2C6H6 + 9O2 → 12CO + 6H2O. Add up the ΔH values for the rearranged reactions to find ΔH for this particular reaction.</span>
<span>
Melatonin is a powerful antioxidant and free radical scavenger that helps 'cool down' excess inflammation.
In fact, melatonin is so integral to the health of your immune system
that a lack of it causes your thymus gland, a key component of your
immune system, to shrink in size.1
Because melatonin is a strong antioxidant and is able to cross the
blood-brain barrier, it is thought to help protect against Alzheimer's
disease as well as brain aging.
In one study, artificially aged mice treated with melatonin had reduced
oxidative stress and markers of cerebral aging and neurodegeneration,
indicating the melatonin offered both neuroprotective and anti-aging
effects.2
In another study, researchers revealed that combining daily exercise
with the daily intake of melatonin appeared to have a synergistic effect
against brain deterioration in mice with Alzheimer's disease-associated
mutations.3 Improvements in behavior, learning and memory were noted.
Melatonin's immediate precursor is the neurotransmitter serotonin,
which is a major player in regulating and giving a lift to your mood.
And, like serotonin, melatonin plays important roles in your physical
and mental health. Studies have shown that insufficient melatonin
production can set you up for:</span>
Answer:
Our world will never be the same. Our beaches will be submerged, many towns, cities, states, and even countries will be partially if not completely submerged. All these human cities being flooded will kill thousands of people, pollute the ocean, and lose billions of dollars.
Explanation:
From Boyle's law the volume of a fixed mass of a gas is inversely proportional to the pressure at a constant absolute temperature. Thus; K = PV Hence; P1V1 =P2V2 0.5 × 24 = 4× P2 P2 = 12/4 = 3 atm Therefore; the pressure will go from 24 atm to 3 atm
Answer:
1) 5 protons, 2) 5, 3) boron, 4) 6 Neutrons, 5) 10.811 ≈ 11, 6) Boron-9
