Answer:
3.61 * 10 ²⁴atoms.
Explanation:
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
w = 582 g
m = 194 g/mol
The number of moles can be calculated from the above formula , and substituting the respective values ,
n = w / m = 582 g / 194 g/mol = 3 mol
In the molecular formula of caffeine ,
<u>In 1 mole of caffeine their are - 2 moles of Oxygen.
</u>
Therefore , in 3 moles of Caffeine there will be 6 moles of oxygen.
As well know ,
one mole of any substance contains 6.023*10²³ atoms,
Therefore , in 6 mol of oxygen = 6 * 6.023*10²³ atoms = 3.61 * 10 ²⁴atoms.
Atomic mass unit is the standard unit that is used for indicating mass on an atomic or molecular scale
Answer:

Explanation:
Hello,
In this case, the enthalpy of combustion is understood as the energy released when one mole of fuel, in this case octene, is burned in the presence of oxygen and is computed with the enthalpies of formation of the fuel, carbon dioxide and water as shown below (oxygen is circumvented as it is a pure element):

Thus, since we already know the enthalpy of combustion of the fuel, for carbon and water we have -393.5 and -241.8 kJ/mol respectively, thereby, the enthalpy of combustion turns out:

Best regards.