Chapter 15.4, Problem 41SSC

Interpretation Introduction

Interpretation:

The conclusion about the stabilities of compounds is to be drawn relative to the elements in their standard states.

Concept introduction:

Table includes the value of standard enthalpies of formation of some compounds.

Standard enthalpy of formation is the heat change when one mole of substance is formed from its elements in standard conditions of temperature and pressure.

A compound is stable if it is associated with low energy.

Answer to Problem 41SSC

All the compounds are stable relative to the elements in their standard states.

Explanation of Solution

From the table it can be seen that standard enthalpies of all four compounds is negative.

And standard enthalpies of elements in pure state is considered zero always.

So compounds have low energy than their respective elements. So compounds are more stable.

Conclusion

Any compound having negative value of standard enthalpy of formation is more stable than its corresponding elements from which it is formed.