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Completing an exothermic profile
Energy is released from the reaction to produce ammonia.
Figure 8 shows part of the reaction profile for the reaction between nitrogen and hydrogen to produce ammonia.
Complete Figure 8. You should:
- complete the profile line
- label the energy level of the reactants and the product
- label the overall energy change.
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Marking points
- 1 Completes an exothermic profile whose product level is below the reactant level.
- 2 Correctly labels the reactant and product energy levels.
- 3 Labels the overall energy change between the two levels.
Full-mark answer
Continue the curve up to an activation-energy peak and down to a product horizontal line below the supplied reactant line. Label the upper line reactants (nitrogen and hydrogen), the lower line product (ammonia), and show the downward overall energy change between them.
Why this answer loses marks
I drew the products above the reactants and labelled an upward overall energy change.
Energy is released, so the product level must be below the reactant level and the overall change must be shown downward.