The reaction is actually endothermic because delta H is positive, indicating that it absorbing heat.
Answer:
The blood will contain 750 grams of O2
Explanation:
Volume of blood in the human body = 15 deciliters
Mass of hemoglobin per deciliter of blood = 15 grams
Mass of hemoglobin in 50 deciliters of blood = 50×15 = 750 grams
Since all the hemoglobin molecules are saturated with O2, mass of O2 in the blood will be the same as mass of hemoglobin molecules in the blood.
Therefore, mass of O2 in the blood is 750 grams
The area used to be covered by an ocean
Given information : Sample of 
We need to find the moles of Chlorine in the given sample.
We can say that we need to find moles from the given atoms.
Relation between mole and atom is given by : 
Where
is Avogadro number.


On solving the above equation , atoms(unit) gets cancelled out and we get 0.0286 mol.
In the given sample the moles of Chlorine (Cl) is 0.0286 mol , so option A is correct.