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Maru [420]
2 years ago
10

Using the following thermochemical data, what is the change in enthalpy for the following reaction?

Chemistry
1 answer:
slavikrds [6]2 years ago
7 0

Answer:

D. -120.9 kJ

Explanation:

According to Hess's law ,the total enthalpy change for a reaction is the sum of all changes regardless of the stages or the steps of the reaction.

CaO + 2HCl \rightarrow CaCl_{2} + H_{2}O\ (\Delta H = -186\ kJ)....(1)

CaO + H_{2}O\rightarrow Ca(OH)_{2}\ (\Delta H = - 65 \ kJ)

(this reaction should be reversed in order to reach the required reaction )

On reversing the reaction the sign of \Delta H get reversed.

(In this case change sign from '-' to'+'. Hence  \Delta H = + 65 kJ)

CaO + 2HCl \rightarrow  CaCl_{2} + H_{2}O\ (\Delta H = - 186\ kJ)....(1)

Ca(OH)_{2}   \rightarrow  CaO + H_{2}O\ (\Delta H = + 65 kJ )......(2)

Adding equation (1) and (2)

Ca(OH)_{2} + 2HCl \rightarrow CaCl_{2} + 2H_{2}O[tex][tex]Delta H = - 186 + 65 = - 121\kJ

Delta H = - 121\kJ (It is nearly equal to -120.9 kJ)

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Answer:

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Explanation:

The general equilibrium of a constant product solubility, ksp, is:

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<em>Where Ksp is defined as:</em>

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When the solution is oversaturated, AB is produced.

Now, in a unsaturated solution, the [A⁺] [B⁻] is less than the maximum amount that can be dissolved. That means:

[A⁺] [B⁻] = Q < Ksp

Q is defined in the same way than Ksp, just in Q the system is not in equilibrium.

Right answer is:

<h3>Q < Ksp</h3>
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