Molecular is every element present in the compound eg C2H6, empirical is the smallest whole number ratio of elements in a compound so that would be CH3 as you divide by the highest common factor. Some compounds only have 1 formula if they are simple or have no common factors. Eg methane, CH4 is its molecular and empirical because its the simplest whole number ratio and includes every element in the molecule
Urea is highly soluble in water. When it is allowed to dissolve in water in the presence of heat, it will yield ammonia and carbon dioxide. The reaction is shown below:
<span>NH2-CO-NH2 + H2O </span>⇒ 2 NH3 + CO2
As you can observe in the stoichiometric equations, 1 molecule of water can dissolve with 1 mole of urea.
Answer : The enthalpy of the reaction = -1839.6 KJ
Solution : Given,
= -520.0 KJ/mole
= -1699.8 KJ/mole
The balanced chemical reaction is,
Formula used :
We know that the standard enthalpy of formation of the element is equal to Zero.
Therefore, the enthalpy of formation of (Mn) and (Al) is equal to zero.
Now, put all the values in above formula, we get
![\Delta (H_{f})_{reaction}=[2moles\times (-1699.8 KJ/mole)}+3moles\times (0\text{ KJ/mole}})]-[(3moles\times(-520.0KJ/mole }+4moles\times(0\text{ KJ/mole})]](https://tex.z-dn.net/?f=%5CDelta%20%28H_%7Bf%7D%29_%7Breaction%7D%3D%5B2moles%5Ctimes%20%28-1699.8%20KJ%2Fmole%29%7D%2B3moles%5Ctimes%20%280%5Ctext%7B%20KJ%2Fmole%7D%7D%29%5D-%5B%283moles%5Ctimes%28-520.0KJ%2Fmole%20%7D%2B4moles%5Ctimes%280%5Ctext%7B%20KJ%2Fmole%7D%29%5D)
= (-3399.6) + (1560)
= -1839.6 KJ
Answer:
A
Explanation:
the correct answer is A
This is the sidereal month. It is measured against the background stars. However, the Earth is also orbiting the Sun, and the moon needs extra time to catch up to its previous position relative to the Sun.
