Definition of Filtration
Filtration is a process utilized to separate solids from liquids or gases using a filter medium that enables the fluid to pass through however not the solid.
The term “filtering” applies whether the filter is mechanical, biological, or physical. The fluid that travels through the filter is called the filtrate.
The filter medium might be a surface filter, which is a solid that traps solid particles, or a depth filter, which is a bed of material that traps the solid particles.
Filtration is normally an imperfect process. Some fluid remains on the feed side of the filter or embedded in the filter media and some small solid particulates discover their way through the filter.
As a chemistry and engineering method, there is always some lost product, whether it’s the liquid or solid being collected.
Uses of filtration
The procedure of filtration is used to separate insoluble particles from liquids. It can be performed with several types of filter media. The nature of the precipitate and other factors determine which filter medium needs to be used. The most hassle-free ways of filtration are either through a filter paper or through a filter crucible.
Methods of filtration
Filtration Through Filter Paper
Filtration by a glass funnel and filter paper is normally a slow procedure. As the mixture is poured onto the filter paper, the solvent (water) goes through leaving behind the suspended particles on the filter paper. Filter papers are offered in a variety of porosities (pore sizes). Which pore size is to be utilized, depends upon the size of particles in the precipitate.
The filter paper must be big enough so that it is one-fourth to one-half filled with precipitate at the end of filtering. The funnel should, in turn, be big enough for its rim to extend 1 to 2 cm above the top circumference of the paper. If the process of filtration is to run smoothly, the stem of the funnel ought to stay continuously loaded with liquid as long as there is liquid in the cone-shaped part.
The stem of the funnel must be several inches long so that it can extend a few centimeters down into the receiving beaker, and the tip needs to touch the side of the beaker. In this way, the filtrate runs down the side of the beaker without sprinkling.
Folding of Filter Paper
The folding of filter paper is necessary and the following points should be kept in mind. The paper should be folded twice. The first fold ought to be along with the size of the paper. The second fold ought to be such that the edges do not quite match. The paper must be opened on a slightly larger area. This provides a cone with 3-fold thickness halfway around and one thickness the other halfway around, and an apex angle is very slightly greater than 60 degrees.
The paper may then be inserted into a 60-degree funnel, dampened with water, and firmly pressed down. The filtering operation could be very time consuming if it were not aided by a gentle suction as the liquid passes through the stem. This suction cannot be established unless the paper is tightly all around its upper circumference.
Fluted Filter Paper
The rate of filtration through a cone-shaped funnel can be considerably increased using a Fluted Filter Paper. For the preparation of such a paper, the common filter paper is folded in such a way that a fan-like plan with alternate elevations and depressions at different folds is acquired.
Filtration Through Filter Crucibles
Another convenient method to filter a precipitate is by suction through a crucible. Two types of crucibles are typically utilized.
1. Gooch Crucible
It is made of porcelain having a perforated bottom which is covered with paper pulp or a filter paper cut to its size. Quick filtration can be done by placing the Gooch crucible in a suction filtering apparatus. It works for the filtration of precipitates, which require to be sparked at high temperatures. If its perforations are covered with asbestos mat then it might be used to filter solutions that react with paper e.g., concentrated HCl and KMnO4solutions.
2. Sintered glass crucible
A sintered glass crucible is a glass crucible with a permeable glass disc sealed into the bottom. It is extremely convenient to use because no preparation is required just like the Gooch crucible.
Examples of filtration
While filtering is a crucial separation technique in a lab, it’s also common in everyday life.
- The kidneys are an example of a biological filter. Blood is filtered by the glomerulus. Essential molecules are reabsorbed back into the blood.
- Air-condition units and many vacuum cleaners utilize HEPA filters to remove dust and pollen from the air.
- Water in an aquifer is fairly pure because it has been filtered through sand and permeable rock in the ground.
MCQs with Answers
- What is the primary purpose of filtration?
- A) To mix solids with liquids
- B) To separate solids from liquids or gases
- C) To create a suspension
- D) To increase the solubility of solids
Answer: B
- What is the fluid that passes through the filter called?
- A) Residue
- B) Precipitate
- C) Filtrate
- D) Solvent
Answer: C
- Which of the following is NOT a type of filter medium?
- A) Surface filter
- B) Depth filter
- C) Mechanical filter
- D) Biological filter
Answer: C
- What is the purpose of folding filter paper in filtration?
- A) To increase its size
- B) To create a cone with a 60-degree angle
- C) To decrease its porosity
- D) To make it rigid
Answer: B
- How does fluted filter paper differ from regular filter paper?
- A) It is made of a different material
- B) It has a fan-like shape with elevations and depressions
- C) It is coated with chemicals
- D) It is transparent
Answer: B
- What is a Gooch crucible used for in filtration?
- A) Rapid filtration at low temperatures
- B) Slow filtration at high temperatures
- C) Filtration of volatile substances
- D) Filtration of gases
Answer: A
- Which type of crucible has a permeable glass disc sealed into the bottom?
- A) Gooch crucible
- B) Porcelain crucible
- C) Sintered glass crucible
- D) Ceramic crucible
Answer: C
- What is an example of a biological filter mentioned in the tutorial?
- A) Coffee filter
- B) Kidneys
- C) HEPA filter
- D) Aquifer filter
Answer: B
- In filtration through filter paper, why should the stem of the funnel extend into the receiving beaker?
- A) To splash the filtrate
- B) To reduce filtration speed
- C) To facilitate the flow of filtrate down the side of the beaker
- D) To block the filtration process
Answer: C
- What is the role of a sintered glass crucible in filtration?
- A) Slow filtration at high temperatures
- B) Rapid filtration at low temperatures
- C) Filtration of volatile substances
- D) Filtration of gases
- Answer: A
- Which filtration method is commonly used for precipitates that require high-temperature ignition?
- A) Filtration through filter paper
- B) Filtration through Gooch crucible
- C) Filtration through fluted filter paper
- D) Filtration through sintered glass crucible
Answer: B
- What is the angle of the apex in a folded filter paper cone?
- A) 45 degrees
- B) 60 degrees
- C) 75 degrees
- D) 90 degrees
Answer: B
- What is the primary purpose of a depth filter in filtration?
- A) To trap solid particles
- B) To increase filtration speed
- C) To reduce porosity
- D) To facilitate splashing
Answer: A
- What does HEPA stand for in the context of filtration?
- A) High Efficiency Particulate Air
- B) Highly Elastic Paper Apparatus
- C) Hydrophobic Emission Prevention Assembly
- D) Heat Exchanging Particle Absorber
Answer: A
- In the context of filtration, what does the filtrate refer to?
- A) Solid particles
- B) Filter medium
- C) The fluid that passes through the filter
- D) The stem of the funnel
Answer: C
- Which of the following is an example of an everyday item that uses a filter?
- A) A hammer
- B) A refrigerator
- C) A vacuum cleaner with a HEPA filter
- D) A chair
Answer: C
- What is the nature of the filtrate in filtration?
- A) Solid
- B) Liquid
- C) Gas
- D) Gel
Answer: B
Frequently Asked Questions (FAQs) about Filtration
- What is filtration?
- Filtration is a process used to separate solids from liquids or gases using a filter medium, allowing the fluid to pass through while retaining the solid.
- Are there different types of filter media in filtration?
- Yes, there are surface filters (solid traps) and depth filters (beds of material) used as filter media in filtration.
- Is filtration a perfect process?
- No, filtration is normally an imperfect process. Some fluid may remain on the feed side, and small solid particles may find their way through the filter.
- What are the primary uses of filtration?
- Filtration is primarily used to separate insoluble particles from liquids. It is commonly employed in labs and everyday life.
- What are the two most convenient ways of filtration mentioned in the tutorial?
- Filtration through filter paper and filtration through filter crucibles, such as Gooch Crucible and Sintered glass crucible.
- Why is filtration through filter paper considered a slow process?
- Filtration through filter paper is slow because, as the mixture is poured onto the filter paper, the solvent (water) passes through, leaving the suspended particles on the filter paper.
- What factors determine the choice of filter medium in filtration?
- The nature of the precipitate and other factors determine the choice of filter medium in filtration.
- Why is folding of filter paper necessary in filtration?
- Folding of filter paper is necessary to create a cone with specific thickness and angle, aiding in the filtration process.
- How can the rate of filtration through a cone-shaped funnel be increased?
- The rate of filtration can be increased using a Fluted Filter Paper, which is prepared by folding the common filter paper in a fan-like plan.
- What is a Gooch Crucible used for in filtration?
- A Gooch Crucible, made of porcelain with a perforated bottom, is used for rapid filtration, especially for precipitates that require high-temperature ignition.
- What is a sintered glass crucible, and how is it used in filtration?
- A sintered glass crucible is a glass crucible with a permeable glass disc sealed into the bottom. It is used in filtration without requiring preparation, similar to the Gooch crucible.
- Can you provide examples of filtration in everyday life?
- Yes, examples include the kidneys acting as biological filters, air-condition units and vacuum cleaners using HEPA filters, and water in an aquifer being naturally filtered through sand and permeable rock.
- How does folding of filter paper contribute to the filtration process?
- Folding of filter paper creates a cone with specific thickness and angle, allowing for efficient filtration. It also aids in establishing gentle suction during the filtration process.
- What is the purpose of a Fluted Filter Paper in filtration?
- A Fluted Filter Paper, with a fan-like plan, is used to considerably increase the rate of filtration through a cone-shaped funnel.
- Can filtration be used to filter gases?
- Yes, filtration through crucibles, such as the Gooch Crucible and Sintered glass crucible, allows for the filtration of gases.
Wrap up
Filtration is a process employed to separate solids from liquids or gases using a filter medium, allowing the fluid to pass through while retaining the solid components. This tutorial explores the definition, uses, methods, and examples of filtration.
Definition of Filtration:
- Filtration involves the separation of solids from fluids or gases through a filter medium, which can be mechanical, biological, or physical. The fluid that passes through the filter is termed the filtrate.
Uses of Filtration:
- Filtration is utilized to separate insoluble particles from liquids and can be performed using various filter media. The choice of filter medium depends on the nature of the precipitate and specific requirements.
Methods of Filtration:
- Filtration Through Filter Paper:
- This method involves a slow process where a mixture is poured onto filter paper. The solvent passes through, leaving suspended particles on the filter paper.
- Folding of Filter Paper:
- Folding of filter paper is crucial for effective filtration. The paper is folded twice to create a cone, enhancing the filtration process.
- Fluted Filter Paper:
- Filtration rate through a cone-shaped funnel can be increased using fluted filter paper, created by folding common filter paper in a fan-like pattern.
- Filtration Through Filter Crucibles:
- This method involves suction filtration through crucibles, including the Gooch Crucible and Sintered glass crucible.
- Gooch Crucible:
- Made of porcelain, it has a perforated bottom covered with paper pulp or filter paper. Suitable for quick filtration, especially for precipitates requiring high-temperature ignition.
- Sintered Glass Crucible:
- A glass crucible with a permeable glass disc sealed into the bottom. Convenient to use without preparation, similar to the Gooch crucible.
Examples of Filtration:
- Filtration is not only a crucial separation technique in labs but is also prevalent in everyday life. Examples include the kidneys acting as biological filters, air-condition units and vacuum cleaners using HEPA filters, and natural filtration of water through sand and permeable rock in aquifers.
This comprehensive tutorial covers the fundamental aspects of filtration, providing insights into its definition, diverse applications, various methods, and real-world examples. Understanding filtration is essential for both scientific processes and everyday applications.