Reversible Reactions & Equilibria Flashcards

All 7 cards in this deck

What does the symbol $\rightleftharpoons$ show in a chemical equation?

The reaction is reversible — it can go both forwards and backwards.
e.g. $\mathrm{CuSO_4.5H_2O \rightleftharpoons CuSO_4 + 5H_2O}$

What is meant by dynamic equilibrium?

The forward and backward reactions happen at the same time at equal rates, so the amounts of reactants and products stay constant.

What are the steps of an experiment to show that this reaction is reversible?
e.g. $\mathrm{CuSO_4.5H_2O \rightleftharpoons CuSO_4 + 5H_2O}$

1. Heat the hydrated (blue) crystals: the solid goes white and steam/water is produced.
2. Add water to the white anhydrous solid: it goes blue again and heat is released.
3. Changing the conditions changed the direction of the reaction.

In the Haber process, which raw materials are the nitrogen and the hydrogen obtained from?

Nitrogen from the air; hydrogen from natural gas.

What is the balanced equation for the formation of ammonia in the Haber process?

$\mathrm{N_2} + 3\mathrm{H_2} \rightleftharpoons 2\mathrm{NH_3}$

State the three conditions used in the Haber process.

A temperature of 450 °C, a pressure of 200 atmospheres and an iron catalyst.

True or false? In the Haber process all of the nitrogen and hydrogen is converted into ammonia.

False. The reaction is reversible and reaches a dynamic equilibrium, so some nitrogen and hydrogen always remain.