Explanation:
At sea level, the atmospheric pressure would be a little over 100 kPa (one atmosphere or 760 mm Hg). If we climb to the top of Mount Everest (the highest mountain in the world at 29,029 feet or 8848 meters), the atmospheric pressure will drop to slightly over 30 kPa (about 0.30 atmospheres or 228 mm Hg).
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The combining of hydrogen and oxygen gas into liquid=H2O (water) is a compound or a molecule because it is 2 different elements combined with chemical bonds so its Chemical. B
Explanation:
For reacting with 8.75 grams of oxygen, 1.08 grams of hydrogen is required.
The given balanced equation has been:
\rm O_2\;+\;2\;H_2\;\rightarrow\;H_2OO2+2H2→H2O
From the equation, 1 mole of oxygen reacts with 2 mole of hydrogen to give 1 mole of water.
The mass of oxygen has been: 8.75 g,
Moles = \rm \dfrac{weight}{molecular\;weight}molecularweightweight
Moles of oxygen = \rm \dfrac{8.75}{32}328.75
Moles of oxygen = 0.27 mol
Since,
1 mole Oxygen = 2 mole hydrogen
0.21 mol oxygen = 0.54 mol hydrogen
Mass of hydrogen = moles \times× molecular weight
Mass of hydrogen = 0.54 \times× 2
Mass of hydrogen = 1.08 grams.
Thus, for reacting with 8.75 grams of oxygen, 1.08 grams of hydrogen is required.
Answer : The enthalpy of the reaction is, -2552 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given enthalpy of reaction is,
The intermediate balanced chemical reactions are:
(1) 
(2) 
(3) 
(4) 
Now we have to revere the reactions 1 and multiple by 2, revere the reactions 3, 4 and multiple by 2 and multiply the reaction 2 by 2 and then adding all the equations, we get :
(when we are reversing the reaction then the sign of the enthalpy change will be change.)
The expression for enthalpy of the reaction will be,
Therefore, the enthalpy of the reaction is, -2552 kJ/mole
