A. Ne
B. NaCL
C. Trail Mix
D. graphene
B. energy level of outer electrons
C. nuclear charge
D. number of valence electrons
Explanation:
A diatomic molecule is defined as the molecule which contains two atoms.
For example, a molecule has two atoms of hydrogen.
Molar mass of a molecule is 2.0 g/mol. Therefore, calculate the mass of 2.0 moles of diatomic hydrogen as follows.
No. of moles =
2.0 mol =
mass = 1 g
therefore, we can conclude that total mass of 2.0 moles of diatomic hydrogen is 1 g.
diatomic hydrogen is written as H2 (2.02 grams H2) <------- if each hydrogen atom is 1.01 grams, then two hydrogen atoms are 2.02 grams 2.0 moles H2 X 2.02 grams H2 ------------- (divide to cancel moles) = 4.04 grams/mole H2 ÷ one mole = 4.04 grams H2
the sum of the enthalpy changes of the intermediate reactions.
the product of the enthalpy changes of the intermediate reactions.
the fraction of the individual enthalpies of the intermediate reactions.
Answer : The correct option is, the sum of the enthalpy changes of the intermediate reactions.
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.
For example :
The formation reaction of CO will be,
The intermediate balanced chemical reaction will be,
(1)
(2)
The expression for enthalpy of formation of CO is,
where,
n = number of moles
By adding reaction 1 and reverse reaction of reaction 2, we get the enthalpy of formation of CO.
Hence, the correct option is, the sum of the enthalpy changes of the intermediate reactions.