Chemical reactions are reversible and may reach a dynamic equilibrium. The direction of some reversible reactions can be altered by changing the reaction conditions.
What does the symbol ⇌ mean in a chemical equation?
The reaction is reversible
The reaction has reached equlibrium
The reaction is faster in the forward than the backward direction
Which of these is a feature of an equilibrium reaction?
The reaction stops taking place
The amounts of each substance in the reaction are the same
The rates of the forward and backward reactions are the same
What happens to the position of equilibrium for the reaction 2SO2(g) + O2(g) ⇌ 2SO3(g) when pressure is increased?
It moves to the left
It moves to the right
It is unchanged
Why does the position of equilibrium for the reaction H2(g) + Cl2(g) ⇌ 2HCl(g) not change when pressure is increased?
The reaction is not reversible
Pressure has no effect on gases
There are the same number of gas molecules on both sides of the reaction
How can the position of equilibrium for the reaction Fe3+(aq) + SCN-(aq) ⇌ FeSCN2+(aq) be moved to the left?
By increasing the pressure
By removing FeSCN2+ ions
By removing Fe3+ ions
The production of ammonia, shown by the equation N2(g) + 3H2(g) ⇌ 2NH3(g), is exothermic. What effect does increasing temperature have on the position of equilibrium?
It moves to the left
The position of equilibrium for a reaction does not change when the temperature is increased. Which of these statements about the reaction is true?
The reaction has no energy change
The reaction is exothermic
The reaction is endothermic
Why is it important to be able to change the position of an equilibrium reaction?
To make the reaction faster
To increase the yield
To make a different set of products
The production of ammonia, shown by the equation N2(g) + 3H2(g) ⇌ 2NH3(g), is exothermic. Which reaction conditions would result in the largest yield?
Low temperature and high pressure
High temperature and low pressure
High temperature and high pressure
Sulfur trioxide is used to manufacture sulfuric acid. Sulfur trioxide is produced through the exothermic reaction, 2SO2(g) + O2(g) ⇌ 2SO3(g). Why is a high temperature of 450°C used to make sulfur trioxide industrially?
To produce sulfur trioxide at a fast rate
To move the equilibrium position to the right
To keep the oxygen as a gas