Answer: The enthalpy of reaction is, -206.18 kJ
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.
The final reaction is
The intermediate balanced chemical reaction will be,
(1)
(2)
(3)
Now adding (2) and (3) and subtracting (1) , we get :
Therefore, the enthalpy of reaction is, -206.18 kJ
The fusion reaction in the sun is a combination of hydrogen atoms fusing to create helium. The fusion reaction in larger stars involve much heavier elements like oxygen and iron. In supernovas, often elements like gold are produced
Answer:
The strength of an acid depends on the concentration of the hydronium ions present in a solution.
Answer: Payback time = 0.0075
Explanation: Since payback time is calculated as:
payback time =
First determine the installation cost:
100 mm thick insulation covers 8.3 m². Then 300 mm covers 24.9 m².
To cover 8.3m² costs £20. Then, the cost to cover 24.9 m² is:
cost =
cost = £60
The cost of putting the insulation is £120, so the total cost is:
total cost = £60 + £120
total cost = £180
Savings per year per 100 mm thick is £80. For 300 mm, the value of annual savings is:
savings =
savings = 240
payback time =
payback time =
payback time = 0.75