What does Hess's law state can be done in order to be able to react solid magnesium with oxygen gas safely (that is, without exp
1 answer:
Answer:
C. The reaction can be broken down and performed in steps
Explanation:
Hess's Law of Constant Heat Summation states that irrespective of the number of steps followed in a reaction, the total enthalpy change for the reaction is the sum of all enthalpy changes corresponding to all the steps in the overall reaction. The implication of this law is that the change of enthalpy in a chemical reaction is independent of the pathway between the initial and final states of the system.
To obtain MgO safely without exposing magnesium to flame, the reaction sequence shown in the image attached may be carried out. Since the enthalpy of the overall reaction is independent of the pathway between the initial and final states of the system, the sum of the enthalpy of each step yields the enthalpy of formation of MgO.
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Answer:
A. for K>>1 you can say that the reaction is nearly irreversible so the forward direction is favored. (Products formation)
B. When the temperature rises the equilibrium is going to change but to know how is going to change you have to take into account the kind of reaction. For endothermic reactions (the reverse reaction is favored) and for exothermic reactions (the forward reaction is favored)
Explanation:
A. The equilibrium constant K is defined as
In any case
aA +Bb equilibrium Cd +dD
where K is:
[] is molar concentration.
If K>>> 1 it means that the molar concentration of products is a lot bigger that the molar concentration of reagents, so the forward reaction is favored.
B. The relation between K and temperature is given by the Van't Hoff equation
Where: H is reaction enthalpy, R is the gas constant and T temperature.
Clearing the equation for we get:
Here we can study two cases: when delta is positive (exothermic reactions) and when is negative (endothermic reactions)
For exothermic reactions when we increase the temperature the denominator in the equation would have a negative exponent so is greater that
and the forward reaction is favored.
When we have an endothermic reaction we will have a positive exponent so will be less than
the forward reactions is not favored.