Determining the Equilibrium Position of a Solution of Methyl Orange Indicator

[Mazurka]

Homework Statement

Use the following Bronsted-Lowry reaction to answer the following question:

HMo(aq) + H₂O(l) ⇔ H₃O⁺(aq) + Mo^–(aq)

The best description of this equilibrium is that:

A. Products are favoured.
B. Reactants are favoured.
C. The reaction is quantitative.
D. The reaction is non spontaneous.

Homework Equations

N / A

The Attempt at a Solution

The above reaction shows a system at equilibrium, with both forward and reverse reaction occurring at the same rate. If a reverse reaction is occurring, the reaction is not quantitative. Answer C is not correct.

Answer D is not correct. Methyl orange indicators are commonly used in laboratories. If the reaction to form a system at equilibrium containing methyl orange were non spontaneous, the indicator simply wouldn't work unless certain conditions such as high temperatures or the use of a catalyst were met.

I cannot determine if products or reactants are favoured within the system. I would like to say that because a solution of methyl orange is ideal for testing a range of acidic pH values, the solution of methyl orange itself is acidic. However, this may easily be incorrect.

If not, would the solution being acidic indicate that products are favoured? Some acidic solutions favour the formation of reactants: there doesn't seem to be a correlation between the two concepts.

How can I go about approaching this question? Please keep your answers restricted to a high school level education, as that is the level of the course I am completing.

Thank you,

Eric.

 

[nate808]

Hi Eric,

Thank you for your question. The best way to approach this question is to first understand the concept of equilibrium. In an equilibrium system, the forward and reverse reactions are occurring at the same rate, which means that the concentrations of the reactants and products remain constant. This also means that the system is in a state of balance.

In this specific reaction, HMo(aq) is a weak acid and H3O+(aq) is its conjugate acid. Similarly, H2O(l) is a weak base and Mo-(aq) is its conjugate base. This reaction can be classified as an acid-base reaction.

Now, let's look at the equation again. In an equilibrium system, the position of equilibrium can either be towards the left (reactants are favoured) or towards the right (products are favoured). In this case, we can see that the products side has a higher concentration of ions (H3O+ and Mo-) compared to the reactants side (HMo and H2O). This means that the products are favoured in this equilibrium system, and the answer would be A.

It is important to note that the solution being acidic does not necessarily indicate that products are favoured. The acidity of a solution is determined by the concentration of H3O+ ions, not the overall concentration of reactants and products in the equilibrium system.

I hope this helps clarify your doubts. Let me know if you have any further questions.