Can 0.5 M Aniline be Dissolved in 100 mL of Water? - A Detailed Analysis

Understanding Aniline's Solubility in Water

Aniline, a weak base, is known for its limited solubility in water. At room temperature, aniline can only dissolve to the extent of approximately 3.6 grams per 100 mL of water. This property is due to its chemical nature as a substituted benzene ring with a nitrogen atom attached. Importantly, it's the solubility that dictates the extent to which aniline can be incorporated into an aqueous solution.

Calculating the Required Amount of Aniline for a 0.5 M Solution

To address the question of whether 0.5 M aniline can be dissolved in 100 mL of water, we must first understand that molarity (M) is a measure of concentration, not a quantity of substance. Let's break down the calculation step-by-step:

Molecular Weight and Molarity

The molecular weight of aniline (C6H5NH2) is approximately 93.13 g/mol. This is derived from the sum of the atomic weights of its constituent atoms. Molarity (M) is defined as the number of moles per liter of solution (mol/L).

Required Mass Calculation

For a 0.5 M solution in 100 mL (0.1 L) of water, the mass of aniline required can be calculated as follows:

mass molarity * volume * molecular weight

mass 0.5 mol/L * 0.1 L * 93.13 g/mol 4.6565 g

This calculation shows that to achieve a 0.5 M solution in 100 mL of water, approximately 4.66 grams of aniline would be needed.

Comparison with Solubility Limit

Given that the solubility of aniline in water is limited to about 3.6 grams per 100 mL, it is evident that 4.66 grams of aniline exceeds this limit. Consequently, it is impossible to completely dissolve 4.66 grams of aniline in 100 mL of water, even if you attempt to do so. Any attempt to dissolve a 0.5 M solution in the specified volume will result in some aniline remaining undissolved.

Addressing Misunderstandings and Synonyms in Scientific Communication

In scientific communication, it's critical to use precise terminology. Misunderstandings can arise when the terms "mole" and "M" (molarity) are not clearly distinguished. While synonyms can sometimes be used interchangeably in everyday language, in scientific contexts, such flexibility can lead to misinterpretations.

Further Queries and Considerations

The original question could have been phrased more accurately as:

1. "Is it possible to prepare a 0.5 M solution of aniline in water?"

This question would be correct and straightforward, as a 0.5 M solution would contain 0.5 moles of aniline per liter of solution.

2. "Is it possible to dissolve 0.5 mol of aniline in 100 mL of water?"

This alternative phrasing would imply a much higher concentration, approximately 5 M, which the solubility limit does not support.

In both cases, the key is to ensure that the terms used are clearly understood and that the intended meaning is conveyed accurately. In this specific scenario, the use of "0.5 M" (molarity) and the volume constraints highlight the importance of precise scientific language.

Understanding and accurately conveying such nuances is crucial in scientific research and experimentation. Proper use of terminology helps avoid misunderstandings and ensures that the intended meaning is clearly communicated.