Sulfur dioxide, SO2\text{SO}_2SO2, and oxygen, O2\text{O}_2O2, react to form sulfur trioxide, SO3\text{SO}_3SO3, in the reversible reaction shown below:
2SO2(g)+O2(g)⇌2SO3(g) 2\text{SO}_2\text{(g)} + \text{O}_2\text{(g)} \rightleftharpoons 2\text{SO}_3\text{(g)} 2SO2(g)+O2(g)⇌2SO3(g)Write an expression for KcK_cKc for this equilibrium and state the units.
A chemist mixes together sulfur dioxide and oxygen in a container of volume 5.0 dm35.0 \text{ dm}^35.0 dm3.
Calculate the amount, in mol\text{mol}mol, of SO3\text{SO}_3SO3 in the equilibrium mixture.
The values of KpK_pKp for this equilibrium at 700 K700\text{ K}700 K and 1000 K1000\text{ K}1000 K are shown below:
| Temperature / K\text{K}K | KpK_pKp / atm−1\text{atm}^{-1}atm−1 |
|---|---|
| 700700700 | 2.5×1042.5 \times 10^{4}2.5×104 |
| 100010001000 | 2.4×10−12.4 \times 10^{-1}2.4×10−1 |
(i) Predict, with a reason, whether the forward reaction is exothermic or endothermic.
The chemist increases the pressure of the equilibrium mixture at the same temperature. State, and explain in terms of KpK_pKp, how you would expect the equilibrium position to change.
