Question

In a study of the formation of HI from its elements, equal amounts of each element were placed in a container, which was then sealed and heated. Explain how Q changes as a function of time.

a) Q increases
b) Q decreases
c) Q remains constant
d) Q is unpredictable

Answer 1

Q remains constant as a function of time when studying the formation of HI from its elements.

Step-by-step explanation:

The formation of HI from its elements involves a reversible reaction represented by the equation: H₂(g) + I₂(g) ↔ 2HI(g) + heat. When equal amounts of hydrogen and iodine are placed in a sealed container and heated, the reaction proceeds until it reaches a state of equilibrium, where the rates of the forward and reverse reactions are equal.

As the reaction proceeds towards equilibrium, the reaction quotient (Q) changes. Initially, there are only reactants present, so Q is low. As the reactants are converted into products, Q increases. However, as the concentration of products increases, the rate of the reverse reaction also increases, causing Q to decrease.

Eventually, when equilibrium is reached, Q remains constant because the rates of the forward and reverse reactions are equal. In conclusion, the answer is c) Q remains constant as a function of time when studying the formation of HI from its elements.