Determination of the Purity of Salt

SohaniSharma

Theory

The purity of the salt compound refers to the percentage of each salt element in the final crystal product. Common salt is often manufactured using evaporation to produce crystals. Common salt is not 100% pure. We can measure the purity percentage of this salt in the lab. The purity can be measured by,

Purity = {(Y - X) / 10} ✕ 100%

Here,

Y = Beaker weight with salt

X = Empty beaker weight

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Objectives

• To know about common salt.
• To know about the purity of salt.
• Learn about the procedure for purity measurement.
• To know about the calculation method of purity.

Apparatus

1. Beaker
2. Filter paper
3. Water
4. Glass rod
5. Weight. balancer
6. Burner etc.

Working Procedure

1. Take an empty beaker and weigh it in a weight balancer.
2. Take 10 gm of salt weighed by weight balancer in a beaker.
3. Added 50 ml of water to the beaker and made a solution of salt.
4. Filter the salt solution with filter paper.
5. Then heat the solution until the water has totally evaporated.
6. Then weighed the beaker with crystal salt again.
7. Calculate the purity of salt.

Calculation

Here,

Y = Beaker weight with salt = 136.34 gm

X = Empty beaker weight = 127.18 gm

So, purity = {(136.34 – 127.18) / 10} ✕ 100% = 91.6%

Result

The purity of the tested salt is 91.6%.

Precautions

1. Salt sample weighting should be perfect.
2. Filtering must be done carefully.
3. When making the solution, you must be careful about the weight.
4. Evaporation of water must be perfect.
5. The calculation should be done carefully.

Conclusion

In this experiment, the purity of salt is determined.  Common salt is used in the dyeing process. The purity of salt may vary as a result of dyeing. So, the purity of salt should be measured before using it in any dyeing process.

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Ahmedabad