Answer : The enthalpy of combustion per mole of
is -2815.8 kJ/mol
Explanation :
Enthalpy change : It is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f(product)]-\sum [n\times \Delta H^o_f(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f%28product%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f%28reactant%29%5D)
The equilibrium reaction follows:

The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(n_{(CO_2)}\times \Delta H^o_f_{(CO_2)})+(n_{(H_2O)}\times \Delta H^o_f_{(H_2O)})]-[(n_{(C_6H_{12}O_6)}\times \Delta H^o_f_{(C_6H_{12}O_6)})+(n_{(O_2)}\times \Delta H^o_f_{(O_2)})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%28n_%7B%28CO_2%29%7D%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CO_2%29%7D%29%2B%28n_%7B%28H_2O%29%7D%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28H_2O%29%7D%29%5D-%5B%28n_%7B%28C_6H_%7B12%7DO_6%29%7D%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28C_6H_%7B12%7DO_6%29%7D%29%2B%28n_%7B%28O_2%29%7D%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28O_2%29%7D%29%5D)
We are given:

Putting values in above equation, we get:
![\Delta H^o_{rxn}=[(6\times -393.5)+(6\times -285.8)]-[(1\times -1260)+(6\times 0)]=-2815.8kJ/mol](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%286%5Ctimes%20-393.5%29%2B%286%5Ctimes%20-285.8%29%5D-%5B%281%5Ctimes%20-1260%29%2B%286%5Ctimes%200%29%5D%3D-2815.8kJ%2Fmol)
Therefore, the enthalpy of combustion per mole of
is -2815.8 kJ/mol
Answer:
2.81 × 10⁶ mm³
2.81 × 10⁻³ m³
Explanation:
Step 1: Given data
Length (l): 250 mm
Width (w): 225 mm
Thickness (t): 50 mm
Step 2: Calculate the volume of the textbook
The book is a cuboid so we can find its volume (V) using the following expression.
V = l × w × t = 250 mm × 225 mm × 50 mm = 2.81 × 10⁶ mm³
Step 3: Convert the volume to cubic meters
We will use the relationship 1 m³ = 10⁹ mm³.
2.81 × 10⁶ mm³ × 1 m³ / 10⁹ mm³ = 2.81 × 10⁻³ m³
To balance a reaction, we must say to it that the number of elements in one side is equal to the other side. For a combustion reaction such as the one given, we first need to balance the number of carbon atoms, then the hydrogen atoms and lastly the oxygen atoms.
<span>C4H10 + 13/2O2 → 4CO2 + 5H2O.</span>
Answer: The atom count for each element on the reactant side of a balanced chemical equation is equal to the atom count for each element on the product side of the same equation
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products formed must be equal to the mass of reactants taken.
In order to get the same mass on both sides, the atoms of each element must be balanced on both sides of the chemical equation.

Thus there are 4 atoms of hydrogen on reactant as well as product side.
Also there are 2 atoms of oxygen on reactant as well as product side.
According to the report of US Environmental Protection
Agency, majority of large dose radiation exposure comes from natural background
radiation sources particularly the radioactive gases radon and thoron. This two
gases form when naturally occurring elements decay. However in the case of
man-made sources, the largest dose comes from medical x-rays.