Preparation of Standard Solution of Oxalic Acid

Introduction

A standard unit of Oxalic acid is solution is used as primary standard solution in specific volume of solvent. It is prepared to use as primary standard substance.

What is Oxalic acid?

Oxalic acid is an organic product with the molecular formula of “2H2O4. Its IUPAC name is Ethanedioic acid. The product consists of dicarboxylic acid. It is a weak acid, exists in the white colour crystalline form.

Figure 1 − Oxalic acid

Oxalic acid gives colourless solution inwater. The molecular weight of Oxalic acid is 90.03g/mol. This product is stronger reducing agent than Acetic acid . The food items rich in Oxalic acid are good for health. However, it has certain harmful effects on human bodies too. This product can lead to kidney stones and many other complicated issues. Naturally, this product is found in Dihydrate form as $\mathrm{C_{2}H_{2}O_{4}.H_{2}O}$.

Aim

This experiment aims to prepare a standard solution M/10 or 0.1M of Oxalic acid.

Theory

The Hydrated Oxalic acid exists in nature with molecular formula of $\mathrm{C_{2}H_{2}O_{4}.H_{2}O}$, and mass is 126 g/mol. The standard M/10 Oxalic acid solution is carried out by mixing 12.6g of Oxalic acid/litre. 3.15g of Oxalic acid crystals are required to mixin water for 250 mL of the solution.

Materials required

These are the following materials necessary for the experiment −

• Chemical balance

• Watch glass

• Weight box

• 250mL beaker

• Glass rod

• 250mL measuring flask

• Wash bottle

• Weighing tube

• Oxalic acid

• Funnel

• Funnel stand

• Distilled water

Procedures

The following process is followed in theexperiment −

Figure 2 − Molecular structure of Oxalic acid

• A watch glass is used for the reaction after cleaning it with distilled water followed by drying.

• The watch glass should be weighed and the data is noted in a notebook.

• An exact amount of 3.15g of Oxalic acid is weighed properlyand data should be noted in the notebook.

• The Oxalic acid should be transferred carefully from the watch glass to a measuring glass using a funnel.

• The watch glass is washed to remove the unwanted particles sticking inside. This process is done with the help of a wash bottle. The volume of the distilled water should never exceed 50mL.

• The funnels are required to wash thoroughly to move excess particles into measuring glass with the aid of a wash bottle. A small amount of water is used for cleaning the funnel. The distilled water again should not go beyond the level of 50mL.

• The funnel is to be washed with distilled water to relocate the solution into the measuring flask.

• The measuring flask is turned on until Oxalic acid dissolves.

• A proper amount of distilled water is added to the measuring flask with the help of wash bottle. The water should always remain below the etched mark on the flask.

• The last few millilitres of distilled water drops should be added into the measuring flask until the water level touches the mark.

• The stopper is added to the mouth of the flask and then the flask should be shaken carefully to turn the solution uniform. The solution of M/10 Oxalic acid should be obtained.

Observation and Result

The observation and the result of the experiment are mentioned below −

Weight of the watch glass	W1g
Weight of the watch glass + Oxalic acid	W1 + 3.15g
Weight of Oxalic acid	3.15g
Volume of distilled water	250cm3

Table 1 − Observation of experiment

Result

250cm3 of M/10 Oxalic acid solution of is derived.

Precautions

Certain precautions should be followed −

• The weight of the Oxalic acid crystals is taken properly. The weight bars should be of $\mathrm{2g\:+\:1g\:+\:100mg\:+\:50mg}$.

• The watch glass should be washed and dried properly so every grain of Oxalic acid crystal can be poured from it.

• A pipette should be used to add the extra few drops of distilled water to avoid addition of excess water.

• During titration, few drops of dilute $\mathrm{H_{2}SO_{4}}$ solution should be added to the flask heated at around 60°C -70°C.

Conclusion

Oxalic acid is quite an abundant product found in different food items consumed in daily life. It also appears in the simplest form of Dicarboxylic acid. Oxalic acid is generally white and is obtained in octahedral crystals. This compound can be synthesized in laboratory following certain precautions. It is generally found in dihydrate form.

FAQs

1. How did Oxalic acid derive its name?

Early researchers who separated Oxalic acid from flower plants belong to the genus oxalis. These flowers were commonly referred to as wood-sorrels.

2. What are the harmful effects of Oxalic acid?

This compound is found in various food products, may be harmful to humans when this product meets skin. Excess ingestion of this product can lead to fatal consequences.

3. What is meant by a standard solution?

A standard solution is referred to the solution of concentration. A normal solution is prepared made by mixing a particular volume of solvent