Question

Match the words in the left column to the appropriate blanks in the sentences on the right. Note that some words may be used more than once and some may not be used.
1. breaking
2. forming
3. positive
4. negative
5. twice
6. half
A. The reaction involves___five blue-blue and twenty blue-red bonds and then____twenty blue-red bonds. Enthalpies for bond breaking are always_____.
B. In the depicted reaction, both reactants and products are assumed to be in the gas phase. There are___as many molecules of in the products, delta S is___for this reaction

Answer 1

Answer:

A. Breaking; forming; positive.

B. Twice; half.

Explanation:

A. The reaction involves breaking five blue-blue and twenty blue-red bonds and then forming twenty blue-red bonds. Enthalpies for bond breaking are always positive.

B. In the depicted reaction, both reactants and products are assumed to be in the gas phase. There are twice as many molecules of gas in the products, delta S is half for this reaction.

Bond enthalpy refers to the amount of energy that is required to break a mole of a particular bond and it's an endothermic reaction, therefore it is always positive.

However, bond forming is always an exothermic reaction because energy is released, therefore, it is always negative. This simply means that, the breaking of a bond is an endothermic reaction (positive) while the formation of a bond is an exothermic reaction (negative).