Answer: The equation for kinetic energy is 
Explanation:
Kinetic energy is the energy possessed by the virtue of object's motion. It is defined as the work needed to move a body of a given mass from rest to its velocity.
Mathematically,

where,
m = mass of the body
v = velocity of the body.
Hence, above equation relates kinetic energy to the mass and velocity of the body.
Answer:
There is an extra O2 molecule left over
Explanation:
Melting (solid to liquid)
The answer is predict, because it fits, and because someone can predict the outcome of something.
Answer:
dS= 1.79*169.504
j/k = 303.41 j/k
Explanation:
Fe3O4(s) + 4H2(g) --> 3Fe (s)+ 4H2O(g)
dS(Fe3O4) =146.4 j/k
dS(H2) =130.684
dS(Fe) =27.78
dS(H2O) =188.825
dSrxn = dS[product]-dS[reactants]
= 3*dS(Fe)+ 4*dS(H2O)-[1*dS(Fe3O4)+ 4dS(H2)]
= [3*27.78 +4*188.825-146.4 -4*130.684] j/k = 169.504 j/k
This is the dS for 1mole Fe3O4
for 1.79 mols Fe3O4
dS= 1.79*169.504 j/k = 303.41 j/k