The food colouring in the glass of tap water began to dissolve after about 3 minutes, but there was still some segregation and faint colouring at the bottom of the glass. There were noticeable amounts of colourants at the bottom of the glass of cold water, and the food colourants were still somewhat separated from one another.

 

After 6 minutes, I noted that the coloration in the heated glass of water had taken on a lilac-purple hue and was almost entirely dissolved. The tap water began transforming into a deeper purple, but there was still some division where the red and blue food colorings were still discernible. Despite the separation of the food colourants still being apparent, the cold water glass exhibited a slight purple hue.

 

This experiment's hot water glass uniformly diffused and acquired a lilac or lavender colour after ten minutes. Despite the presence of a few red and blue colorants, the tap water glass was nearly completely dissolved and purple in color, while the cold water glass gradually continued to change to a purple tint.

 

After 30 minutes, the glass of tap water had a mid-purple tint and no separations, whereas a dark purple tinge and virtually no partitioning could be seen in the cold water glass.

The fastest mixture occurred with the hot water, tuning completely purple after about a minute or two. While the slowest rate occurred with the cold water where it took the full length of time for the two colours to no longer appear distinguishable. 

Write ONE description of how EACH of the following separation methods is used in science and industry. Include a picture of each separation method. 

1. Filtration 

filtration: is a separation technique used to separate the components of a mixture containing an undissolved solid in a liquid by using a funnel lined with filter paper to retain the solids while letting the liquid through.

2. Distillation

Distillation is a physical separation based on the vaporisation of the different components of the mixture to be separated. Typically, a mixture is heated, vapors are produced, separated, and then condensed back into a liquid. As a result, each component can be separately recuperated in different fractions.

3. Chromatography

Chromatography is based on the principle where molecules in mixture applied onto the surface or into the solid, and fluid stationary phase (stable phase) is separating from each other while moving with the aid of a mobile phase.

The mixtures are of two main types: homogeneous mixtures is uniform throughout and heterogeneous mixtures are not uniform throughout (ingredients are distributed unequally). Air is a homogeneous mixture of different gases, including oxygen, nitrogen, carbon dioxide, and water vapor. Concrete is a heterogeneous mixture of cement, aggregates, sand and water. (BYJU'S, 2023)

Filtration is used in water treatment and sewage treatment plants. Looking at the water treatment plant, on an industrial level during filtration, the clear water passes through filters that have different pore sizes and are made of different materials (such as sand, gravel, and charcoal). These filters remove dissolved particles and germs, such as dust, chemicals, parasites, bacteria, and viruses. Activated carbon filters also remove any bad odors. (CDC, 2022)

To separate a mixture of liquids, the liquid can be heated to force components, which have different boiling points, into the gas phase. The gas is then condensed back into liquid form and collected. Repeating the process on the collected liquid to improve the purity of the product is called double distillation. Although the term is most commonly applied to liquids, the reverse process can be used to separate gases by liquefying components using changes in temperature and/or pressure.

A plant that performs distillation is called a distillery. The apparatus used to perform distillation is called a still.  (Anne Marie Helmenstine, 2020)

Chromatography is vital for any chemical research, because a chemical reaction rarely gives us 100 % pure product; we usually get some side-products, and some unreacted starting material that we need to separate from our desired product.

Pharmaceutical companies use chromatography both to prepare large quantities of extremely pure materials, and also to analyze the purified compounds for trace contaminants. Chromatography is used for quality control in the food industry, by separating and analyzing additives and proteins.  (ChemBAM, n.d.)

 

Like in CSI and Law and Order, forensic testing utilizes chromatography in the form of crime scene testing (the analysis of blood or cloth samples), arson verification (identifying the chemicals responsible for a fire to see whether there was foul play) or blood testing after death to determine levels of alcohol, drugs or poisonous substances in the body.  (Chromatography Today, 2014)