Systematic Analysis of Anions

Introduction

The analysis of anions in a systematic manner has turned out to be an integral part of inorganic salts that are rich in their qualitative properties. The entire process of analysis serves either of the two objectives. They are two understand the quality and quantity of the anions present.

Aim of the experiment

The aim of this experiment is to find out the total number of radicals present in its anionic form. This type of radical is very common in the mixture constituting salts that have inorganic properties in them.

Theory

The systematic analysis of anions was designed to find out and acknowledge the different types of radicals comprising bases and acids. The salts that are formed by inorganic properties comprise basic and acidic properties. The acidic compounds have a decent component that defines their inorganic traits. This component is known for being “crystalline solids” due to the presence of “geometric shapes”. This set of properties is known to carry some charges that are termed radicals. The salt analysis comes in two basic aspects - one of them is product solubility and the common ion effect.

Procedure of the experiment

Figure 1 − Performing flame test

Performing flame test, Creative Commons Zero, Public Domain Dedication, via Wikimedia

Sr.No	Experiment	Observation	Inference
1	Preliminary action	The salt used in this format is not observed to have a proper colour.	$\mathrm{Fe^{2+}\:,\:Fe^{3+}\:,\:Ni^{2+}\:and\:Co^{2+}}$ ions are not present in this first stage of the reaction.
	The look and other physical properties of the element.	The look of these salts mainly differs in the form of colour shades. They include the colour green, brown, pink and the shade blue.	The inferences of every colour are listed respectively - $\mathrm{Fe^{2+}\;,\:Ni^{2+}\:and\:Cu^{2+}}$. The inference for the colour brown is called Fe2+. The inference may vary from $\mathrm{Co^{2+}\:and\:Mn^{2+}}$ if the salt is pink in colour. The salt which is $\mathrm{Cu^{2+}}$ is known for the colour blue.
2	The action that is going to be observed for the presence of some heat in the element.	The action of heat that has been observed is divided into three variations. The gas is colourless with a strong and pungent odour turning red litmus blue. The litmus paper turns blue as they have reddish brown vapours coming out. The colour changes on temperature as it is white during cold and hot gives the colour of yellow.	The colourless gas can give $\mathrm{NH_{4}^{+}}$ salts. In the case of reddish-brown vapours, they tend to give $\mathrm{NO^{+}_{3}}$. The colour changing due to temperature gives an inference of $\mathrm{(Zn)^{2+}}$.
3	The third step of the procedure is called a flame test. In this specific test, a small drop of hydrochloric acid in its concentrated form is known to give a proper paste as a texture to the salt. The paste must be put on top of the flame of aBunsen burner.	The observation of this flame test is divided into four halves. The first one says the flames start with an apple green colour. The second observation of this flame is that it has a crimson red colour. The third colour of the flame is brick red and the final one is bluish green.	The inferences are respectively stated as $\mathrm{Ba^{2+}\:,\:Sr^{2+}\:,\:Ca^{2+}\:and\:Cu^{2+}}$

Table 1 − Experiment procedure

Observation and results

• Carbonate anion − The gas that is emitted is $\mathrm{CO_{2}}$ which has a very strong effervescence. They have a dilute acid $\mathrm{H_{2}SO_{4}}$ that can change the colour of lime water to a milky white look.

Figure 2 − Dry test

• Sulphide anion − The colour changes over to purple or violet right after a single drop of sodium nitroprusside is dropped in the solution.

• Sulphite anion − The presence of this anion is formed by clearing a white precipitate with barium chloride. The solution of this element disappears when they react with hydrochloric acid in its dilute condition. The other observation is that it starts to release a gas of sulphur dioxide.

Precautions

The precautions are as follows -

• The label must be read to understand the chemical content.

• Aprons that are made of durable fabrics are a must.

• Smell chemical vapours under the strict supervision of seniors and peers.

• The chemical should never touch the tongue.

• Never try to mix a drop of acid in a test tube of water.

• Never touch the test tube with bare hands as they are very hot.

• Make sure to put on a pair of safety goggles.

• Keep a safe distance from the chemicals and fire, and should follow precautions.

Conclusion

The tutorial explains the ways salt can be used to see the total amount of anions used. The procedure shows the methods of conducting this experiment in the right way. Inorganic salt has different colours due to certain ions. Lastly, the tutorial comes to its end with the basic precautions that must be exercised for the sake of everyone’s safety.

FAQs

1. What is the significance of the common ion effect in the field of inorganic chemistry?

The significance of the common ion effect in the field of organic chemistry is that it works either with a weak acid or base to prevent it from going through the process of ionization.

2. What is meant by the qualitative analysis of anions?

The qualitative analysis of anions is known to give a proper count of the number of anions and cations found in a given chemical compound. This analytical breakdown can be conducted on a single element as well to cover the same objective of finding the right number of anions and cations present in that element.

3. What is the total number of anions present in the form of a group?

The total number of anions that are present in the form of a group makes a total of two. One of them is known as Group 16 which holds a charge of - 2. The second one is known by the name Group 15 with a - 3 charge.