Substances have different tendencies to donate or accept electrons. When a really good donor meets a great acceptor, the chemical reaction releases a lot of energy. Oxygen (O2) is the best electron acceptor and is used in many aerobic reactions (reactions with oxygen). Hydrogen gas (H2) is a good electron donor.
When O2 and H2 are combined, along with a catalyst, water (H2O) is formed. This example of a redox reaction can be written like this:

No mountains in the world are increasing in size
Answer:-3463 kJ and -3452kJ
Explanation:
ΔU is the change in internal energy of a system and its formula is;
ΔU = q + w
Where q represents heat transferred into or out of the system. Its value is positive when heat is transfer into the system and negative when heat is produced by the system.
W represents the work done on or by the system. Its value is positive when work is done on the system and negative when it is done by the system.
For the system in this question, we see that it produces heat which means heat is transferred out of the system, therefore the value of q is negative, it can also be seen that work is done by the system which means that w is also negative.
Therefore,
ΔU = -q-w
ΔU = -3452 kJ – 11kJ
= - 3463kJ
ΔH is the change in the enthalpy of a system and its formuls is;
ΔH = ΔU + Δ(PV)
By product rule Δ(PV) becomes ΔPV + PΔV
At constant pressure ΔP = 0. Therefore,
ΔH = -q-w + PΔV
w is equals to PΔV, So:
ΔH = -q
ΔH = -3452kJ
Answer:
8 moles
Explanation:
When we are asked to convert from grams of a substance into moles, we have to use the substance's molar mass.
Meaning that for this problem, we'll <em>use the molar mass of hydrogen peroxide</em> (H₂O₂), as follows:
There are 8 moles in 272 grams of hydrogen peroxide.
