Answer: c. 179 kJ/mol
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 Hess’s law, the chemical equation can be treated as algebraic expressions 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.
Given:
(1)
(2)
(3)
(4)
On subtracting eq (1) from eq (2) we have:
-
Hence the enthalpy change for the raection is 179.0 kJ/mol.
Sound production is not chemical change.
A specific combination of bonded atoms which always react in the same way, regardless of the particular carbon skeleton is known as the functional group. These are specific groups of atoms or bonds within organic molecules that accounts for the characteristic chemical reactions of those molecules. Examples of functional groups are the Carbonyl group, alkyl Halides, aldehydes and ketones among others.
Answer:
Number of particles = 2.0 g*(6.0 x 10^23 particles/mol) / 20.18 g/mol
Option C is correct
Explanation:
Step 1: Data give
Mass of Ne = 2.0 grams
Molar mass of neon = 20.18 g/mol
Number of Avogadro = 6.0 *10^23 /mol
Step 2: Calculate number of moles of neon
Moles Ne = Mass of ne / Molar mass of ne
Moles Ne = 2.0 / 20.18 g/mol
Moles Ne = 0.099 moles
Step 3: Calculate nulber of particles
Number of particles = 6.022*10^23 / mol * 0.099 moles = 5.96 *10^22
Number of particles = 6.022*10^23 * (2.0g/ 20.18g/mol)
Number of particles = 2.0 g*(6.0 x 10^23 particles/mol) / 20.18 g/mol
Option C is correct
